chore(deps): update actions/setup-go action to v6 (GoogleCloudPlatform#3092)

Author: renovate-bot

.github/workflows/ci-main.yaml

@@ -37,7 +37,7 @@ jobs:
         DOTNET_INSTALL_DIR: "./.dotnet"
       with:
         dotnet-version: '9.0'
-    - uses: actions/setup-go@v5
+    - uses: actions/setup-go@v6
       with:
         go-version: '1.25'
     - name: Go Unit Tests

.github/workflows/ci-pr.yaml

@@ -41,7 +41,7 @@ jobs:
         DOTNET_INSTALL_DIR: "./.dotnet"
       with:
         dotnet-version: '9.0'
-    - uses: actions/setup-go@v5
+    - uses: actions/setup-go@v6
       with:
         go-version: '1.25'
     - name: Go Unit Tests