refactor: move workflowpattern into modules/actions (#37717)

`act/workflowpattern` in runner is only consumed by Gitea and dead code
there. Move it to this repo. Use `modules/glob` for glob pattern match.

---------

Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/actions/workflowpattern/workflow_pattern.go

@@ -0,0 +1,65 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package workflowpattern
+
+import (
+	"strings"
+
+	"code.gitea.io/gitea/modules/glob"
+)
+
+type WorkflowPattern struct {
+	negative bool
+	glob     glob.Glob
+}
+
+func CompilePatterns(patterns ...string) ([]*WorkflowPattern, error) {
+	ret := make([]*WorkflowPattern, 0, len(patterns))
+	for _, pattern := range patterns {
+		cp, err := glob.CompileWorkflow(pattern)
+		if err != nil {
+			return nil, err
+		}
+		ret = append(ret, &WorkflowPattern{glob: cp, negative: strings.HasPrefix(pattern, "!")})
+	}
+	return ret, nil
+}
+
+// Skip returns true if the workflow should be skipped per paths/branches semantics.
+func Skip(sequence []*WorkflowPattern, input []string) bool {
+	allSkipped := true
+	for _, file := range input {
+		shouldSkip := true
+		for _, item := range sequence {
+			if item.negative {
+				// "!README.md" doesn't match "README.md", so "README.md" should be skipped
+				// "!README.md" matches "help.md" but it shouldn't affect "skip or not", because "help.md" might have been skipped by other rules like "docs/*.md"
+				if !item.glob.Match(file) {
+					shouldSkip = true
+				}
+			} else if item.glob.Match(file) {
+				// if "*.md" matches "help.md" so it shouldn't be skipped
+				shouldSkip = false
+			}
+		}
+		allSkipped = allSkipped && shouldSkip
+	}
+	return len(sequence) > 0 && allSkipped
+}
+
+// Filter returns true if the workflow should be skipped per paths-ignore/branches-ignore semantics.
+func Filter(sequence []*WorkflowPattern, input []string) bool {
+	for _, file := range input {
+		anyMatched := false
+		for _, item := range sequence {
+			if anyMatched = item.glob.Match(file); anyMatched {
+				break
+			}
+		}
+		if !anyMatched {
+			return false
+		}
+	}
+	return len(sequence) != 0
+}