Merge gitea/act into act/

Merges the `gitea.com/gitea/act` fork into this repository as the `act/`
directory and consumes it as a local package. The `replace github.com/nektos/act
=> gitea.com/gitea/act` directive is removed; act's dependencies are merged
into the root `go.mod`.

- Imports rewritten: `github.com/nektos/act/pkg/...` → `gitea.com/gitea/act_runner/act/...`
  (flattened — `pkg/` boundary dropped to match the layout forgejo-runner adopted).
- Dropped act's CLI (`cmd/`, `main.go`) and all upstream project files; kept
  the library tree + `LICENSE`.
- Added `// Copyright <year> The Gitea Authors ...` / `// Copyright <year> nektos`
  headers to 104 `.go` files.
- Pre-existing act lint violations annotated inline with
  `//nolint:<linter> // pre-existing issue from nektos/act`.
  `.golangci.yml` is unchanged vs `main`.
- Makefile test target: `-race -short` (matches forgejo-runner).
- Pre-existing integration test failures fixed: race in parallel executor
  (atomic counters); TestSetupEnv / command_test / expression_test /
  run_context_test updated to match gitea fork runtime; TestJobExecutor and
  TestActionCache gated on `testing.Short()`.

Full `gitea/act` commit history is reachable via the second parent.

Co-Authored-By: Claude (Opus 4.7) <noreply@anthropic.com>

act/container/linux_container_environment_extensions.go

@@ -0,0 +1,80 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Copyright 2022 The nektos/act Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package container
+
+import (
+	"context"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type LinuxContainerEnvironmentExtensions struct{}
+
+// Resolves the equivalent host path inside the container
+// This is required for windows and WSL 2 to translate things like C:\Users\Myproject to /mnt/users/Myproject
+// For use in docker volumes and binds
+func (*LinuxContainerEnvironmentExtensions) ToContainerPath(path string) string {
+	if runtime.GOOS == "windows" && strings.Contains(path, "/") {
+		log.Error("You cannot specify linux style local paths (/mnt/etc) on Windows as it does not understand them.")
+		return ""
+	}
+
+	abspath, err := filepath.Abs(path)
+	if err != nil {
+		log.Error(err)
+		return ""
+	}
+
+	// Test if the path is a windows path
+	windowsPathRegex := regexp.MustCompile(`^([a-zA-Z]):\\(.+)$`)
+	windowsPathComponents := windowsPathRegex.FindStringSubmatch(abspath)
+
+	// Return as-is if no match
+	if windowsPathComponents == nil {
+		return abspath
+	}
+
+	// Convert to WSL2-compatible path if it is a windows path
+	// NOTE: Cannot use filepath because it will use the wrong path separators assuming we want the path to be windows
+	// based if running on Windows, and because we are feeding this to Docker, GoLang auto-path-translate doesn't work.
+	driveLetter := strings.ToLower(windowsPathComponents[1])
+	translatedPath := strings.ReplaceAll(windowsPathComponents[2], `\`, `/`)
+	// Should make something like /mnt/c/Users/person/My Folder/MyActProject
+	result := strings.Join([]string{"/mnt", driveLetter, translatedPath}, `/`)
+	return result
+}
+
+func (*LinuxContainerEnvironmentExtensions) GetActPath() string {
+	return "/var/run/act"
+}
+
+func (*LinuxContainerEnvironmentExtensions) GetPathVariableName() string {
+	return "PATH"
+}
+
+func (*LinuxContainerEnvironmentExtensions) DefaultPathVariable() string {
+	return "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+}
+
+func (*LinuxContainerEnvironmentExtensions) JoinPathVariable(paths ...string) string {
+	return strings.Join(paths, ":")
+}
+
+func (*LinuxContainerEnvironmentExtensions) GetRunnerContext(ctx context.Context) map[string]any {
+	return map[string]any{
+		"os":         "Linux",
+		"arch":       RunnerArch(ctx),
+		"temp":       "/tmp",
+		"tool_cache": "/opt/hostedtoolcache",
+	}
+}
+
+func (*LinuxContainerEnvironmentExtensions) IsEnvironmentCaseInsensitive() bool {
+	return false
+}