Remove enable_cast_wayland_server flag on cast linux bots

In line with the removal of ENABLE_CAST_WAYLAND_SERVER buildflag.

This reverts commit 663bb259.

Bug: 1043215
Test: CQ
Change-Id: I6840eaf5423d49c7d5c96f275b3461d367702146
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2006470Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Jiaqi Han <jiaqih@google.com>
Cr-Commit-Position: refs/heads/master@{#738238}

tools/mb/mb_config.pyl

@@ -1335,11 +1335,11 @@
     # Cast Linux takes very long in linking, possibly due to being on GCE
     # (crbug/794423).
     'cast_release_bot': [
-      'cast', 'cast_exo', 'release_bot', 'minimal_symbols',
+      'cast', 'release_bot', 'minimal_symbols',
     ],
 
     'cast_release_trybot': [
-      'cast', 'cast_exo', 'release_trybot',
+      'cast', 'release_trybot',
     ],
 
     'cast_audio_release_bot': [
@@ -2140,10 +2140,6 @@
       'gn_args': 'is_cast_audio_only=true'
     },
 
-    'cast_exo': {
-      'gn_args': 'enable_cast_wayland_server=true',
-    },
-
     'cfi': {
       'gn_args': 'is_cfi=true',
     },

tools/mb/mb_config_buckets.pyl

@@ -2020,13 +2020,11 @@
     ],
     'cast_release_bot': [
       'cast',
-      'cast_exo',
       'release_bot',
       'minimal_symbols'
     ],
     'cast_release_trybot': [
       'cast',
-      'cast_exo',
       'release_trybot'
     ],
     'cast_audio_release_bot': [
@@ -2924,10 +2922,6 @@
       'gn_args': 'is_cast_audio_only=true'
     },
 
-    'cast_exo': {
-      'gn_args': 'enable_cast_wayland_server=true'
-    },
-
     'cfi': {
       'gn_args': 'is_cfi=true'
     },