[build] Use default snapshot for all testing variants

Bug: v8:7964
Change-Id: I540aa0f9b64969f70822f3956d5f9d0a0ea0fde2
Reviewed-on: https://chromium-review.googlesource.com/1206710Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55649}

infra/mb/mb_config.pyl

@@ -628,14 +628,10 @@
       'gn_args': 'is_debug=true v8_enable_backtrace=true',
     },
 
-    'v8_use_multi_snapshots': {
-      'gn_args': 'v8_use_multi_snapshots=true',
-    },
-
     'debug_bot': {
       'mixins': [
         'debug', 'shared', 'goma', 'v8_enable_slow_dchecks',
-        'v8_use_multi_snapshots', 'v8_optimized_debug'],
+        'v8_optimized_debug'],
     },
 
     'debug_trybot': {
@@ -722,7 +718,7 @@
     },
 
     'release_bot': {
-      'mixins': ['release', 'static', 'goma', 'v8_use_multi_snapshots'],
+      'mixins': ['release', 'static', 'goma'],
     },
 
     'release_trybot': {