[test] Remove always-on flag from test variant

Wasm code GC is on by default now.

R=machenbach@chromium.org

No-Try: true
Change-Id: Ib24e68f431876ecb91e7ae6ef6bc6cc08c2ea0c0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1910942Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64908}

tools/testrunner/local/variants.py

@@ -25,7 +25,6 @@ ALL_VARIANT_FLAGS = {
   "stress": [["--stress-opt", "--always-opt", "--no-liftoff",
               "--no-wasm-tier-up", '--stress-lazy-source-positions']],
   "stress_js_bg_compile_wasm_code_gc": [["--stress-background-compile",
-                                         "--wasm-code-gc",
                                          "--stress-wasm-code-gc"]],
   "stress_incremental_marking": [["--stress-incremental-marking"]],
   # Trigger stress sampling allocation profiler with sample interval = 2^14