test: wire master's new fps_telemetry_opt_in guard

Master added runtime/tests/test_fps_telemetry_opt_in.py in bb5fcce without an
add_test() entry. It is a source-only guard over runtime/src/main.cpp and
passes, so it joins the same list as the other 15. 30 tests, still under four
seconds.

This is the pattern the earlier commit was meant to prevent recurring -- worth
noting it recurred within a day, which is the argument for a CI check rather
than a convention.

recompiler/CMakeLists.txt

@@ -383,6 +383,7 @@ if(BUILD_TESTING)
                 capture_history
                 default_renderer_guards
                 fmv_quiet_guards
+                fps_telemetry_opt_in
                 launcher_vulkan_option
                 overlay_candidate_capacity
                 overlay_decodable_fallback