[ci] Add size-balanced test sequencer for better shard distribution (facebook#35458)

Jest's default test sequencer sorts alphabetically, causing large test
files
(eg ReactDOMFloat-test.js at 9k lines,
ReactHooksWithNoopRenderer-test.js at 4k
lines) to cluster in shard 3/5. This made shard 3/5 average 117s vs 77s
for
other shards, a 52% slowdown. I'm using filesize as a rough proxy for
number of tests.

This custom sequencer sorts tests by file size and distributes large
files evenly across all shards
instead of clustering them together.

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35458).
* __->__ facebook#35458
* facebook#35459

DiffTrain build for [d6cae44](facebook@d6cae44)

Author: pull[bot]

compiled/facebook-www/REVISION

@@ -1 +1 @@
-b731fe28cc492cb36c51c89866f5b63a3ffae2aa
+d6cae440e34c6250928e18bed4a16480f83ae18a

compiled/facebook-www/REVISION_TRANSFORMS

@@ -1 +1 @@
-b731fe28cc492cb36c51c89866f5b63a3ffae2aa
+d6cae440e34c6250928e18bed4a16480f83ae18a

compiled/facebook-www/React-dev.classic.js

@@ -1499,7 +1499,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.3.0-www-classic-b731fe28-20251217";
+    exports.version = "19.3.0-www-classic-d6cae440-20260106";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-dev.modern.js

@@ -1499,7 +1499,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.3.0-www-modern-b731fe28-20251217";
+    exports.version = "19.3.0-www-modern-d6cae440-20260106";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-prod.classic.js

@@ -606,4 +606,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-classic-b731fe28-20251217";
+exports.version = "19.3.0-www-classic-d6cae440-20260106";

compiled/facebook-www/React-prod.modern.js

@@ -606,4 +606,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-modern-b731fe28-20251217";
+exports.version = "19.3.0-www-modern-d6cae440-20260106";

compiled/facebook-www/React-profiling.classic.js

@@ -610,7 +610,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-classic-b731fe28-20251217";
+exports.version = "19.3.0-www-classic-d6cae440-20260106";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-profiling.modern.js

@@ -610,7 +610,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-modern-b731fe28-20251217";
+exports.version = "19.3.0-www-modern-d6cae440-20260106";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/ReactART-dev.classic.js

@@ -20468,10 +20468,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.3.0-www-classic-b731fe28-20251217",
+        version: "19.3.0-www-classic-d6cae440-20260106",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.3.0-www-classic-b731fe28-20251217"
+        reconcilerVersion: "19.3.0-www-classic-d6cae440-20260106"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -20506,7 +20506,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.3.0-www-classic-b731fe28-20251217";
+    exports.version = "19.3.0-www-classic-d6cae440-20260106";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/ReactART-dev.modern.js

@@ -20239,10 +20239,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.3.0-www-modern-b731fe28-20251217",
+        version: "19.3.0-www-modern-d6cae440-20260106",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.3.0-www-modern-b731fe28-20251217"
+        reconcilerVersion: "19.3.0-www-modern-d6cae440-20260106"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -20277,7 +20277,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.3.0-www-modern-b731fe28-20251217";
+    exports.version = "19.3.0-www-modern-d6cae440-20260106";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&