gha: disable setup-go cache for golangci job

Since commit e3cf217 actions/setup-go@v4 uses caching
implicitly, and olangci/golangci-lint-action also uses caching.

These two caches clash, resulting in multiple warnings in CI logs.

The official golangci-lint-action solution is to disable caching
for setup-go job (see [1]). Do the same.

[1] golangci/golangci-lint-action#704

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

.github/workflows/validate.yml

@@ -32,6 +32,7 @@ jobs:
       - uses: actions/setup-go@v4
         with:
           go-version: "${{ env.GO_VERSION }}"
+          cache: false # golangci-lint-action does its own caching
       - name: install deps
         run: |
           sudo apt -q update