[flags] fix typo in variants.py

regarding --no-enable-experimental-regexp-engine

Bug: v8:10941
Change-Id: I9c3d9f8616b4ba9464ae699e1edf458c1f994952
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2421812
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70030}

tools/testrunner/local/variants.py

@@ -62,7 +62,7 @@ INCOMPATIBLE_FLAGS_PER_VARIANT = {
   "turboprop": ["--turbo-inlining", "--interrupt-budget=*", "--no-turboprop"],
   "code_serializer": ["--cache=after-execute", "--cache=full-code-cache", "--cache=none"],
   "no_local_heaps": ["--concurrent-inlining", "--turboprop"],
-  "experimental_regexp": ["-no--enable-experimental-regexp-engine"],
+  "experimental_regexp": ["--no-enable-experimental-regexp-engine"],
 }
 
 # Flags that lead to a contradiction under certain build variables.