Change GOTOOLCHAIN version in CI workflow

Update GOTOOLCHAIN environment variable for unit tests.

Author: leo-aa88

.github/workflows/ci.yml

@@ -71,8 +71,9 @@ jobs:
       # (".out" becomes a separate argument / package path).
       - name: Unit tests
         shell: bash
+        env:
+          GOTOOLCHAIN: go1.22.0+auto
         run: |
-          go env -w GOTOOLCHAIN=go1.23.0+auto \
           go test -v \
             -race \
             -count=1 \