Revert "pass all arguments to stubtest as is"

This reverts commit df856cd.

Author: Akuli

tests/stubtest_stdlib.py

@@ -18,6 +18,8 @@ def run_stubtest(typeshed_dir: Path) -> int:
     platform_allowlist = "{}.txt".format(sys.platform)
     combined_allowlist = "{}-py{}{}.txt".format(sys.platform, sys.version_info.major, sys.version_info.minor)
 
+    ignore_unused_allowlist = "--ignore-unused-allowlist" in sys.argv[1:]
+
     cmd = [
         sys.executable,
         "-m",
@@ -30,7 +32,8 @@ def run_stubtest(typeshed_dir: Path) -> int:
         "--allowlist",
         str(allowlist_dir / version_allowlist),
     ]
-    cmd += sys.argv[1:]
+    if ignore_unused_allowlist:
+        cmd += ["--ignore-unused-allowlist"]
     if (allowlist_dir / platform_allowlist).exists():
         cmd += ["--allowlist", str(allowlist_dir / platform_allowlist)]
     if (allowlist_dir / combined_allowlist).exists():