ci: Upgrade to golangci-lint v2 for Go 1.24+ compatibility

- Update .golangci.yml to v2 format with version field
- Change linters.enable to linters.enabled (v2 syntax)
- Update CI to use golangci-lint-action@v8 with v2.5.0
- Aligns local (v2.5.0) and CI versions as requested
- Fixes Go version compatibility issue (v1 built with Go 1.23)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: nielspeter

.github/workflows/ci.yml

@@ -78,7 +78,7 @@ jobs:
         go-version: '1.24'
 
     - name: golangci-lint
-      uses: golangci/golangci-lint-action@v4
+      uses: golangci/golangci-lint-action@v8
       with:
-        version: v1.62
+        version: v2.5.0
         args: --timeout=5m

.golangci.yml

@@ -1,27 +1,17 @@
+# golangci-lint v2 configuration
+version: "2"
+
 run:
   timeout: 5m
-  tests: false
-  skip-dirs:
-    - vendor
-    - third_party
+  tests: false  # Don't analyze test files
 
 linters:
-  enable:
+  enabled:
     - errcheck
     - govet
     - ineffassign
     - staticcheck
     - unused
 
-linters-settings:
-  errcheck:
-    check-blank: false
-
 issues:
-  exclude-use-default: true
-  exclude-rules:
-    # Exclude error checks in test files
-    - path: _test\.go
-      linters:
-        - errcheck
-        - staticcheck
+  exclude-use-default: true