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/common/executor_test.go

@@ -45,43 +45,6 @@ func TestNewWorkflow(t *testing.T) {
 	assert.Equal(2, runcount)
 }
 
-func TestNewConditionalExecutor(t *testing.T) {
-	assert := assert.New(t)
-
-	ctx := context.Background()
-
-	trueCount := 0
-	falseCount := 0
-
-	err := NewConditionalExecutor(func(ctx context.Context) bool {
-		return false
-	}, func(ctx context.Context) error {
-		trueCount++
-		return nil
-	}, func(ctx context.Context) error {
-		falseCount++
-		return nil
-	})(ctx)
-
-	assert.NoError(err) //nolint:testifylint // pre-existing issue from nektos/act
-	assert.Equal(0, trueCount)
-	assert.Equal(1, falseCount)
-
-	err = NewConditionalExecutor(func(ctx context.Context) bool {
-		return true
-	}, func(ctx context.Context) error {
-		trueCount++
-		return nil
-	}, func(ctx context.Context) error {
-		falseCount++
-		return nil
-	})(ctx)
-
-	assert.NoError(err) //nolint:testifylint // pre-existing issue from nektos/act
-	assert.Equal(1, trueCount)
-	assert.Equal(1, falseCount)
-}
-
 // concurrencyProbe returns an executor recording the peak number of concurrent copies. Copies
 // block until wantActive are in flight so the peak is exact without sleeping, and later copies
 // find the gate already open so the last one still finishes with no partner left.
@@ -223,10 +186,3 @@ func TestExecutorFinallyReturnsFinallyErrorWithOriginal(t *testing.T) {
 		t.Fatalf("finally error = %q, want both cleanup and original error", err)
 	}
 }
-
-func TestConditionalNot(t *testing.T) {
-	cond := Conditional(func(context.Context) bool { return false })
-	if !cond.Not()(context.Background()) {
-		t.Fatal("inverted conditional should be true")
-	}
-}