Move XCTestHelpers to TestCaseAccessibilityRule.swift (#4552)

it's only used in that file

Source/SwiftLintFramework/Helpers/XCTestHelpers.swift

@@ -1,29 +0,0 @@
-import SwiftSyntax
-
-enum XCTestHelpers {
-    private static let testVariableNames: Set = [
-        "allTests"
-    ]
-
-    static func isXCTestFunction(_ function: FunctionDeclSyntax) -> Bool {
-        guard !function.modifiers.containsOverride else {
-            return true
-        }
-
-        return !function.modifiers.containsStaticOrClass &&
-            function.identifier.text.hasPrefix("test") &&
-            function.signature.input.parameterList.isEmpty
-    }
-
-    static func isXCTestVariable(_ variable: VariableDeclSyntax) -> Bool {
-        guard !variable.modifiers.containsOverride else {
-            return true
-        }
-
-        return
-            variable.modifiers.containsStaticOrClass &&
-            variable.bindings
-                .compactMap { $0.pattern.as(IdentifierPatternSyntax.self)?.identifier.text }
-                .allSatisfy(testVariableNames.contains)
-    }
-}

Source/SwiftLintFramework/Rules/Lint/TestCaseAccessibilityRule.swift

@@ -143,3 +143,31 @@ private extension ClassDeclSyntax {
         } ?? []
     }
 }
+
+private enum XCTestHelpers {
+    private static let testVariableNames: Set = [
+        "allTests"
+    ]
+
+    static func isXCTestFunction(_ function: FunctionDeclSyntax) -> Bool {
+        guard !function.modifiers.containsOverride else {
+            return true
+        }
+
+        return !function.modifiers.containsStaticOrClass &&
+            function.identifier.text.hasPrefix("test") &&
+            function.signature.input.parameterList.isEmpty
+    }
+
+    static func isXCTestVariable(_ variable: VariableDeclSyntax) -> Bool {
+        guard !variable.modifiers.containsOverride else {
+            return true
+        }
+
+        return
+            variable.modifiers.containsStaticOrClass &&
+            variable.bindings
+                .compactMap { $0.pattern.as(IdentifierPatternSyntax.self)?.identifier.text }
+                .allSatisfy(testVariableNames.contains)
+    }
+}