ci/gha: bump golangci/golangci-lint-action to v5

Since v5 removes caching [1], re-enable setup-go cache.

[1] golangci/golangci-lint-action#1024

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
(cherry picked from commit 6bcc736)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

.github/workflows/validate.yml

@@ -27,12 +27,11 @@ jobs:
       - uses: actions/setup-go@v5
         with:
           go-version: "${{ env.GO_VERSION }}"
-          cache: false # golangci-lint-action does its own caching
       - name: install deps
         run: |
           sudo apt -q update
           sudo apt -qy install libseccomp-dev
-      - uses: golangci/golangci-lint-action@v4
+      - uses: golangci/golangci-lint-action@v5
         with:
           version: v1.53
       # Extra linters, only checking new code from a pull request.