Auto merge of #20729 - jdm:cleanmanifest, r=kichjang

Don't suppress the result of checking the WPT manifest.

This was a mistake I introduced in 8b378120a4.

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python/servo/testing_commands.py

@@ -87,7 +87,7 @@ def run_update(topdir, check_clean=False, rebuild=False, **kwargs):
     from wptrunner import wptlogging
     logger = wptlogging.setup(kwargs, {"mach": sys.stdout})
     wpt_dir = os.path.abspath(os.path.join(topdir, 'tests', 'wpt'))
-    manifestupdate.update(logger, wpt_dir, check_clean, rebuild)
+    return manifestupdate.update(logger, wpt_dir, check_clean, rebuild)
 
 
 @CommandProvider

tests/wpt/mozilla/meta/MANIFEST.json

@@ -60211,11 +60211,11 @@
    "reftest"
   ],
   "css/background_border_padding_crash-ref.html": [
-   "eae17c2be5646f7fa1dc26e5a28a89c527da00e6",
+   "a9b8abdba927b26841acb2405a8a753e4efb2d24",
    "support"
   ],
   "css/background_border_padding_crash.html": [
-   "600d0c014aabfe13f09dec11757d5d7740a5ba74",
+   "068fea92a7884351465963e76306435cf6680b56",
    "reftest"
   ],
   "css/background_clip_a.html": [
@@ -70951,7 +70951,7 @@
    "testharness"
   ],
   "mozilla/webgl/bindBuffer.html": [
-   "659d53041373a6e40b9ab4cbf7e2afad45048377",
+   "3ee0f8120ec78da6584399fef852276b65f9b650",
    "testharness"
   ],
   "mozilla/webgl/bufferData.html": [
@@ -70963,7 +70963,7 @@
    "testharness"
   ],
   "mozilla/webgl/clear.html": [
-   "14cc534be5da96b0cc128d5c44f662b2fdfb294c",
+   "d5a3af49d99e8165aa154c31ca8d846e45094986",
    "testharness"
   ],
   "mozilla/webgl/clearcolor.html": [