LibTest: Fix minor const-correctness issue in TestSuite::find_cases()

Author: https://github.com/awesomekling
Commit: 485958bb6f
Pull-request: https://github.com/SerenityOS/serenity/pull/17557
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibTest/TestSuite.cpp

@@ -94,7 +94,7 @@ int TestSuite::main(DeprecatedString const& suite_name, int argc, char** argv)
 NonnullRefPtrVector<TestCase> TestSuite::find_cases(DeprecatedString const& search, bool find_tests, bool find_benchmarks)
 {
     NonnullRefPtrVector<TestCase> matches;
-    for (auto const& t : m_cases) {
+    for (auto& t : m_cases) {
         if (!search.is_empty() && !t.name().matches(search, CaseSensitivity::CaseInsensitive)) {
             continue;
         }