Fix CI lint job by using golangci-lint-action

The lint job failed because golangci-lint was not installed on the
runner. Replace the manual Task-based approach with the standard
golangci/golangci-lint-action which handles installation and caching.

Set CGO_ENABLED=0 so CGO-only packages are excluded, and add the
missing cgo build constraint to propolis-runner/main.go so it is
correctly skipped when CGO is disabled.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JAORMX

.github/workflows/ci.yaml

@@ -46,13 +46,12 @@ jobs:
           go-version: ${{ env.GO_VERSION }}
           cache: true
 
-      - name: Install Task
-        run: |
-          sh -c "$(curl --location https://taskfile.dev/install.sh)" -- -d -b /usr/local/bin
-
-      - name: Run linter
-        run: |
-          task lint
+      - name: Run golangci-lint
+        uses: golangci/golangci-lint-action@v7
+        with:
+          args: --timeout=5m
+        env:
+          CGO_ENABLED: "0"
 
   build:
     name: Build

runner/cmd/propolis-runner/main.go

@@ -1,6 +1,8 @@
 // SPDX-FileCopyrightText: Copyright 2025 Stacklok, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
+//go:build (linux || darwin) && cgo
+
 // Package main provides the propolis-runner helper binary.
 // This binary is spawned as a subprocess by the propolis framework
 // to run VMs using libkrun's CGO bindings.