Declare TestHelpers as a test target (#6300)

Author: SimplyDanny

CHANGELOG.md

@@ -12,7 +12,10 @@
 
 ### Enhancements
 
-* None.
+* Declare `TestHelpers` as a test target in `Package.swift` to avoid building
+  and linking it in release mode.  
+  [SimplyDanny](https://github.com/SimplyDanny)
+  [#6299](https://github.com/realm/SwiftLint/issues/6299)
 
 ### Bug Fixes
 

Package.swift

@@ -216,7 +216,7 @@ let package = Package(
             ],
             swiftSettings: swiftFeatures + strictConcurrency
         ),
-        .target(
+        .testTarget(
             name: "TestHelpers",
             dependencies: [
                 "SwiftLintFramework"