Update GitHub Actions to use Go 1.24

- Update go.mod to Go 1.24.0 with toolchain go1.24.1
- Update GitHub Actions workflow to use Go 1.24
- Update action versions to v4 (checkout and setup-go)
- Add GOTOOLCHAIN=local to prevent unexpected toolchain downloads
- This matches the local development environment

Author: yaronf

.github/workflows/test.yml

@@ -3,13 +3,15 @@ name: Test
 jobs:
   test:
     runs-on: ubuntu-latest
+    env:
+      GOTOOLCHAIN: local
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v4
         with:
-          go-version: '1.20'
+          go-version: '1.24'
           cache: false
       - name: Test
         run: go test ./...

go.mod

@@ -1,6 +1,8 @@
 module github.com/yaronf/httpsign
 
-go 1.21
+go 1.24.0
+
+toolchain go1.24.1
 
 require (
 	github.com/andreyvit/diff v0.0.0-20170406064948-c7f18ee00883