[test] Bump shards on slowest trybots

NOTRY=true
TBR=sergiyb@chromium.org

Change-Id: Ia7044aa05d5e66ef8fb89fb955604d3d5eb3f1c6
Reviewed-on: https://chromium-review.googlesource.com/1223870
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55845}

infra/testing/builders.pyl

@@ -202,9 +202,9 @@
   'v8_linux_arm_rel_ng_triggered': {
     'tests': [
       {'name': 'mjsunit_sp_frame_access'},
-      {'name': 'mozilla'},
-      {'name': 'test262'},
-      {'name': 'v8testing', 'shards': 7},
+      {'name': 'mozilla', 'shards': 2},
+      {'name': 'test262', 'shards': 2},
+      {'name': 'v8testing', 'shards': 8},
       {'name': 'v8testing', 'variant': 'extra', 'shards': 3},
     ],
   },
@@ -322,8 +322,8 @@
   'v8_linux_arm64_rel_ng_triggered': {
     'tests': [
       {'name': 'mjsunit_sp_frame_access'},
-      {'name': 'mozilla'},
-      {'name': 'test262'},
+      {'name': 'mozilla', 'shards': 2},
+      {'name': 'test262', 'shards': 2},
       {'name': 'v8testing', 'shards': 9},
       {'name': 'v8testing', 'variant': 'extra', 'shards': 4},
     ],