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/runner/testdata/actions/node20/node_modules/deprecation/LICENSE

@@ -0,0 +1,15 @@
+The ISC License
+
+Copyright (c) Gregor Martynus and contributors
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

act/runner/testdata/actions/node20/node_modules/deprecation/dist-node/index.js

@@ -0,0 +1,20 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+class Deprecation extends Error {
+  constructor(message) {
+    super(message); // Maintains proper stack trace (only available on V8)
+
+    /* istanbul ignore next */
+
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, this.constructor);
+    }
+
+    this.name = 'Deprecation';
+  }
+
+}
+
+exports.Deprecation = Deprecation;

act/runner/testdata/actions/node20/node_modules/deprecation/dist-src/index.js

@@ -0,0 +1,14 @@
+export class Deprecation extends Error {
+  constructor(message) {
+    super(message); // Maintains proper stack trace (only available on V8)
+
+    /* istanbul ignore next */
+
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, this.constructor);
+    }
+
+    this.name = 'Deprecation';
+  }
+
+}

act/runner/testdata/actions/node20/node_modules/deprecation/dist-types/index.d.ts

@@ -0,0 +1,3 @@
+export class Deprecation extends Error {
+  name: "Deprecation";
+}

act/runner/testdata/actions/node20/node_modules/deprecation/dist-web/index.js

@@ -0,0 +1,16 @@
+class Deprecation extends Error {
+  constructor(message) {
+    super(message); // Maintains proper stack trace (only available on V8)
+
+    /* istanbul ignore next */
+
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, this.constructor);
+    }
+
+    this.name = 'Deprecation';
+  }
+
+}
+
+export { Deprecation };

act/runner/testdata/actions/node20/node_modules/deprecation/package.json

@@ -0,0 +1,34 @@
+{
+  "name": "deprecation",
+  "description": "Log a deprecation message with stack",
+  "version": "2.3.1",
+  "license": "ISC",
+  "files": [
+    "dist-*/",
+    "bin/"
+  ],
+  "esnext": "dist-src/index.js",
+  "main": "dist-node/index.js",
+  "module": "dist-web/index.js",
+  "types": "dist-types/index.d.ts",
+  "pika": true,
+  "sideEffects": false,
+  "keywords": [
+    "deprecate",
+    "deprecated",
+    "deprecation"
+  ],
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/gr2m/deprecation.git"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "@pika/pack": "^0.3.7",
+    "@pika/plugin-build-node": "^0.4.0",
+    "@pika/plugin-build-types": "^0.4.0",
+    "@pika/plugin-build-web": "^0.4.0",
+    "@pika/plugin-standard-pkg": "^0.4.0",
+    "semantic-release": "^15.13.3"
+  }
+}