Remove unmaintained trybots

Bug: v8:10445
Change-Id: I2d5501fdf7f2c3a7c19176f15d002f4f7f0cc40e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2260564
Commit-Queue: Almothana Athamneh <almuthanna@chromium.org>
Reviewed-by: Liviu Rau <liviurau@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68509}

infra/mb/mb_config.pyl

@@ -217,7 +217,6 @@
       'v8_linux_shared_compile_rel': 'release_x86_shared_verify_heap',
       'v8_linux64_arm64_pointer_compression_rel_ng':
           'release_simulate_arm64_pointer_compression',
-      'v8_linux64_compile_rel_xg': 'release_x64_test_features_trybot',
       'v8_linux64_dbg_ng': 'debug_x64_trybot',
       'v8_linux64_gc_stress_custom_snapshot_dbg_ng': 'debug_x64_trybot_custom',
       'v8_linux64_gcc_compile_dbg': 'debug_x64_gcc',
@@ -232,8 +231,6 @@
       'v8_linux64_asan_rel_ng': 'release_x64_asan_minimal_symbols',
       'v8_linux64_cfi_rel_ng': 'release_x64_cfi',
       'v8_linux64_msan_rel_ng': 'release_simulate_arm64_msan_minimal_symbols',
-      'v8_linux64_sanitizer_coverage_rel':
-          'release_x64_asan_minimal_symbols_coverage',
       'v8_linux64_tsan_rel_ng': 'release_x64_tsan_minimal_symbols',
       'v8_linux64_tsan_isolates_rel_ng':
           'release_x64_tsan_minimal_symbols',
@@ -431,8 +428,6 @@
       'release_bot', 'x64', 'asan', 'lsan'],
     'release_x64_asan_minimal_symbols': [
       'release_bot', 'x64', 'asan', 'lsan', 'minimal_symbols'],
-    'release_x64_asan_minimal_symbols_coverage': [
-      'release_bot', 'x64', 'asan', 'bb', 'coverage', 'lsan', 'minimal_symbols'],
     'release_x64_asan_no_lsan': [
       'release_bot', 'x64', 'asan'],
     'release_x64_asan_no_lsan_verify_heap': [
@@ -593,10 +588,6 @@
       'gn_args': 'is_asan=true',
     },
 
-    'bb': {
-      'gn_args': 'sanitizer_coverage_flags="bb,trace-pc-guard"',
-    },
-
     'cfi': {
       'mixins': ['v8_enable_test_features'],
       'gn_args': ('is_cfi=true use_cfi_cast=true use_cfi_icall=true '

infra/testing/builders.pyl

@@ -391,26 +391,6 @@
       {'name': 'v8testing', 'variant': 'stress_instruction_scheduling'},
     ],
   },
-  # TODO(machenbach): Experimental builder with incomplete configs. Should be
-  # similar to v8_linux64_rel_ng_triggered after testing.
-  'v8_linux64_rel_xg': {
-    'swarming_dimensions' : {
-      'cpu': 'x86-64-avx2',
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'v8initializers'},
-      {'name': 'v8testing', 'shards': 2},
-    ],
-  },
-  'v8_linux64_sanitizer_coverage_rel': {
-    'swarming_dimensions' : {
-      'os': 'Ubuntu-16.04',
-    },
-    'tests': [
-      {'name': 'v8testing', 'shards': 3},
-    ],
-  },
   'v8_linux64_tsan_rel_ng_triggered': {
     'swarming_dimensions' : {
       'os': 'Ubuntu-16.04',