Run target source pattern matching in parallel (yonaskolb#1197)

As this transform closure does not access anything outside of its
closure and does not mutate any singletons, then it seems to be safe
to run this mapping in parallel.

CHANGELOG.md

@@ -10,6 +10,10 @@
 - Fix Monterey macOS shell version, shell login flag for environments [#1167](https://github.com/yonaskolb/XcodeGen/issues/1167) @bimawa
 - Fixed crash caused by a simultaneous write during a glob processing [#1177](https://github.com/yonaskolb/XcodeGen/issues/1177) @tr1ckyf0x
 
+### Changed
+
+- Run target source pattern matching in parallel [#1197](https://github.com/yonaskolb/XcodeGen/pull/1197) @alvarhansen
+
 ## 2.27.0
 
 #### Added

Sources/XcodeGenKit/SourceGenerator.swift

@@ -359,7 +359,7 @@ class SourceGenerator {
  let rootSourcePath = project.basePath + targetSource.path
 
  return Set(
- patterns.map { pattern in
+ patterns.parallelMap { pattern in
  guard !pattern.isEmpty else { return [] }
  return Glob(pattern: "\(rootSourcePath)/\(pattern)")
  .map { Path($0) }