[CodeQuality] Skip DirectInstanceOverMockArgRector outside test classes

[TomasVotruba]

Fixes crash reported in rectorphp/rector#9869.

Problem

DirectInstanceOverMockArgRector called ScopeFetcher::fetch($node) as its first action, before any guard. PHPStan does not assign scope to args of a new expression that mixes an unpacked spread with a named argument, so the fetch threw Scope not available — crashing the entire Rector run.

Worse, this happened in non-test application code. The rule ships in the phpunit-code-quality set, so any project with this argument shape failed its whole run, even though the rule only ever touches Symfony Request/RequestStack mocks inside tests.

// non-test class — crashed the run before this PR
$data = new SomeData(
    ...$request->updateData(),
    user: (string) $request->user()->getKey(),
);

Fix

Gate on TestsNodeAnalyzer::isInTestClass() (resolves via reflection, no scope needed) and drop the eager ScopeFetcher::fetch() entirely. Non-test classes bail out early, before any scope is touched.

-$scope = ScopeFetcher::fetch($node);
-if (! $scope->isInClass()) {
-    return null;
-}
-
-$classReflection = $scope->getClassReflection();
-if (! $classReflection->is(PHPUnitClassName::TEST_CASE)) {
-    return null;
-}
+// run on test classes only, non-test code may lack scope on args and crash the whole run
+if (! $this->testsNodeAnalyzer->isInTestClass($node)) {
+    return null;
+}

Added a skip fixture reproducing the crashing shape in a non-test class.