Don't pass folder in cmake target test-perl-testsuite

Passing arguments to tools/invoke-tests overrides TESTS
and makes it impossible to run individual tests as we
document in the README.md, for example:

    make test-perl-testsuite TESTS="t/23-baseclass.t"

Without this change all tests from t are always executed.

cmake/test-targets.cmake

@@ -93,7 +93,7 @@ endif ()
 find_program(PROVE_PATH prove)
 find_program(UNBUFFER_PATH unbuffer)
 if (PROVE_PATH)
-    set(INVOKE_TEST_ARGS --prove-tool "${PROVE_PATH}" --make-tool "${CMAKE_MAKE_PROGRAM}" --unbuffer-tool "${UNBUFFER_PATH}" --build-directory "${CMAKE_CURRENT_BINARY_DIR}" t)
+    set(INVOKE_TEST_ARGS --prove-tool "${PROVE_PATH}" --make-tool "${CMAKE_MAKE_PROGRAM}" --unbuffer-tool "${UNBUFFER_PATH}" --build-directory "${CMAKE_CURRENT_BINARY_DIR}")
     add_test(
         NAME test-perl-testsuite
         COMMAND "${CMAKE_CURRENT_SOURCE_DIR}/tools/invoke-tests" ${INVOKE_TEST_ARGS}

tools/invoke-tests

@@ -77,8 +77,8 @@ args=()
 # use unbuffer if it was found so e.g. timestamps on OBS builds will be useful
 # note: When executing tests with prove it seems that the output is only flushed after one test has finished unless there's a terminal.
 [[ $unbuffer_path ]] && [[ $unbuffer_path != 'UNBUFFER_PATH-NOTFOUND' ]] && args+=("$unbuffer_path")
-# split TESTS on white-spaces to allow specifying multiple tests as documented
-TESTS=${TESTS:-"-r t xt"}
+# run tests from t only by default
+TESTS=${TESTS:-"t"}
 # shellcheck disable=SC2206
 args+=("$prove_path" $PROVE_ARGS $TESTS)
 (cd "$source_directory" && "${args[@]}")