Skip wasm/many-modules test on a stress bot

The test creates 10000 modules, which runs in less then one second in
release builds, but can take much longer with stress flags and on
special bots.
It timed out on the tsan isolates bot in a variant passing
--stress-wasm-code-gc.
Since the test should only verify that we support more than 1000
modules in a single isolate, we do not need to run it in that variant.
Thus just skip it.

R=fgm@chromium.org

Bug: v8:9814
Change-Id: Ie3a4f62a053b1f7cff2c2206f39ddd71a533ae3e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1845229
Reviewed-by: Francis McCabe <fgm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64153}

test/mjsunit/mjsunit.status

@@ -1129,4 +1129,11 @@
   'harmony/modules-import-15': [SKIP],
 }], # variant == top_level_await
 
+##############################################################################
+['variant == stress_js_bg_compile_wasm_code_gc', {
+  # Runs significantly slower with --stress-wasm-code-gc, problematic
+  # especially in combination with tsan or other slow configurations.
+  'wasm/many-modules': [SKIP],
+}],  # variant == stress_js_bg_compile_wasm_code_gc
+
 ]