Implement webhook branch filter (#7791)

* Fix validate() function to handle errors in embedded anon structs

* Implement webhook branch filter

See #2025, #3998.

vendor/github.com/gobwas/glob/syntax/syntax.go

@@ -0,0 +1,14 @@
+package syntax
+
+import (
+	"github.com/gobwas/glob/syntax/ast"
+	"github.com/gobwas/glob/syntax/lexer"
+)
+
+func Parse(s string) (*ast.Node, error) {
+	return ast.Parse(lexer.NewLexer(s))
+}
+
+func Special(b byte) bool {
+	return lexer.Special(b)
+}