fix: upgrade golangci-lint to v2.8.0 for action v9.2.0 compatibility

The golangci-lint-action v9.2.0 dropped support for golangci-lint v1.x
and requires v2.x versions. The error "golangci-lint v1 is not supported
by golangci-lint-action >= v7" indicates we need to upgrade, not downgrade.

Updated both ci-pipeline.yml and quality-checks.yml from v1.64.5 to v2.8.0
to align with the current golangci-lint major version.

Fixes: #666 (golangci-lint version compatibility error)

.github/workflows/ci-pipeline.yml

@@ -75,7 +75,7 @@ jobs:
       - name: Run golangci-lint (fast)
         uses: golangci/golangci-lint-action@1e7e51e771db61008b38414a730f564565cf7c20 # v9.2.0
         with:
-          version: v1.64.5
+          version: v2.8.0
           working-directory: backend
           args: --config=.golangci-fast.yml --timeout=2m
 

.github/workflows/quality-checks.yml

@@ -75,7 +75,7 @@ jobs:
       - name: Run golangci-lint
         uses: golangci/golangci-lint-action@1e7e51e771db61008b38414a730f564565cf7c20 # v9.2.0
         with:
-          version: v1.64.5
+          version: v2.8.0
           working-directory: backend
           args: --config=.golangci-fast.yml --timeout=2m