refactor: remove unreachable runner code (#1179)

Remove inherited act APIs, configuration branches, and test seams that neither the daemon nor exec can reach. Constant-fold settings both entry points already enforce and consolidate duplicate runner paths.

Major removals:

- Unwired custom action-cache and local-repository-cache implementations.
- Legacy matrix, platform, input, container-reuse, logging, Git remote, and action-replacement configuration paths.
- Unused Docker socket, container network, tar-copy, and platform PTY wrappers.
- Single-implementation filesystem, environment, runner, and expression abstractions.
- Duplicated step-container, command-logging, credential, reusable-workflow, and execution paths.
- Generated client mock boilerplate, obsolete fixtures, test-only seams, stale wrappers, and commented-out code.

This removes 2844 net Go lines while retaining Gitea RPC, event, matrix, input, cache, artifact, action, reusable workflow, Docker, host, exec, and release behavior.

Assisted by Codex (GPT-5).

Reviewed-on: https://gitea.com/gitea/runner/pulls/1179
Reviewed-by: bircni <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>

act/runner/reusable_workflow_test.go

@@ -5,7 +5,6 @@ package runner
 
 import (
 	"context"
-	"errors"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -77,19 +76,11 @@ func TestReusableWorkflowCachedBranchRefRefreshes(t *testing.T) {
 
 func TestNewReusableWorkflowExecutorHoldsCloneLock(t *testing.T) {
 	workflowDir := t.TempDir()
+	require.NoError(t, os.WriteFile(filepath.Join(workflowDir, "reusable.yml"), []byte(":"), 0o644))
 
 	unlockOnce := sync.OnceFunc(git.AcquireCloneLock(workflowDir))
 	defer unlockOnce()
 
-	plannerCalled := make(chan struct{})
-
-	origPlanner := modelNewWorkflowPlanner
-	modelNewWorkflowPlanner = func(string, bool) (model.WorkflowPlanner, error) {
-		close(plannerCalled)
-		return nil, errors.New("stop")
-	}
-	defer func() { modelNewWorkflowPlanner = origPlanner }()
-
 	rc := &RunContext{
 		Config: &Config{},
 		Run:    &model.Run{Workflow: &model.Workflow{Jobs: map[string]*model.Job{}}},
@@ -100,26 +91,18 @@ func TestNewReusableWorkflowExecutorHoldsCloneLock(t *testing.T) {
 	go func() { done <- exec(context.Background()) }()
 
 	select {
-	case <-plannerCalled:
-		t.Fatal("planner ran while clone lock was held")
 	case err := <-done:
-		t.Fatalf("executor returned before planner was reached: %v", err)
+		t.Fatalf("executor returned while clone lock was held: %v", err)
 	case <-time.After(50 * time.Millisecond):
 	}
 
 	unlockOnce()
 
-	select {
-	case <-plannerCalled:
-	case <-time.After(time.Second):
-		t.Fatal("planner not called after lock was released")
-	}
-
 	select {
 	case err := <-done:
 		require.Error(t, err)
 	case <-time.After(time.Second):
-		t.Fatal("executor did not return after planner ran")
+		t.Fatal("executor did not return after lock was released")
 	}
 }