[build] Remove configs for removed mipsel builder

NOTRY=true
TBR=sergiyb@chromium.org

Bug: chromium:890231
Change-Id: Id5934d864f5e90bb3ec918567afe7542a2cf28c6
Reviewed-on: https://chromium-review.googlesource.com/1256770Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56334}

infra/mb/mb_config.pyl

@@ -127,8 +127,6 @@
           'debug_simulate_arm64_asan_edge',
       'V8 Clusterfuzz Linux ASAN arm - debug builder':
           'debug_simulate_arm_asan_edge',
-      'V8 Clusterfuzz Linux ASAN mipsel - debug builder':
-          'debug_simulate_mipsel_asan_edge',
       'V8 Clusterfuzz Linux64 CFI - release builder':
           'release_x64_cfi_clusterfuzz',
       'V8 Clusterfuzz Linux MSAN no origins':
@@ -336,8 +334,6 @@
     'debug_simulate_arm64_no_snap': [
       'debug', 'simulate_arm64', 'shared', 'goma', 'v8_optimized_debug',
       'v8_snapshot_none'],
-    'debug_simulate_mipsel_asan_edge': [
-      'debug_bot', 'simulate_mipsel', 'asan', 'edge'],
 
     # Release configs for simulators.
     'release_simulate_arm': [