downgrade golangci-lint-action to v6

Author: Markus Schwer

.github/workflows/checks.yaml

@@ -12,7 +12,6 @@ defaults:
 
 env:
   GO_VERSION: "1.24.1"
-  GOLANG_CI_VERSION: v1.64.7
 
 jobs:
   lint:
@@ -25,6 +24,4 @@ jobs:
           cache: false
       - uses: actions/checkout@v4
       - name: lint
-        uses: golangci/golangci-lint-action@v7
-        with:
-          version: ${{ env.GOLANG_CI_VERSION }}
+        uses: golangci/golangci-lint-action@v6