feat: include user agent in headers

this will be helpful in the future for debugging customer issues since
it will tell us what version of the plugins (at least the bundler
core) they're using

Author: joseph-sentry

packages/bundler-plugin-core/src/utils/__tests__/Output.test.ts

@@ -693,6 +693,7 @@ describe("Output", () => {
             headers: new Headers({
               Authorization: "token token",
               "Content-Type": "application/json",
+              "User-Agent": "codecov-bundler_plugin/1.9.1",
             }),
             body: JSON.stringify({
               branch: "main",

packages/bundler-plugin-core/src/utils/getPreSignedURL.ts

@@ -7,6 +7,7 @@ import {
   type Span,
 } from "@sentry/core";
 import { z } from "zod";
+import { version } from "../../package.json" with { type: "json" };
 import { FailedFetchError } from "../errors/FailedFetchError.ts";
 import { UploadLimitReachedError } from "../errors/UploadLimitReachedError.ts";
 import { type ProviderServiceParams } from "../types.ts";
@@ -53,6 +54,7 @@ export const getPreSignedURL = async ({
 }: GetPreSignedURLArgs) => {
   const headers = new Headers({
     "Content-Type": "application/json",
+    "User-Agent": `codecov-bundler_plugin/${version}`,
   });
 
   const requestBody: RequestBody = serviceParams;