Avoid to use environment.

scripts/slave/recipes/syzygy/continuous.expected/full_master_client_syzygy_Syzygy_Official.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\kill_processes.py"
     ],
     "name": "taskkill"
   },
   {
@@ skipping 100 matching lines @@
       "--gsutil-py-path",
       "RECIPE_PACKAGE_REPO[depot_tools]\\gsutil.py",
       "--ninja-path",
       "RECIPE_PACKAGE_REPO[depot_tools]\\ninja.exe",
       "--target",
       "Release",
       "--src-dir",
       "[SLAVE_BUILD]\\src",
       "--goma-cache-dir",
       "[GOMA_CACHE]",
+      "--buildbot-buildername",
+      "Syzygy Official",
+      "--buildbot-mastername",
+      "master.client.syzygy",
+      "--buildbot-slavename",
+      "vm331-m3",
       "--ninja-ensure-up-to-date",
       "--",
       "official_build"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
     },
     "name": "compile"
   },
   {
@@ skipping 188 matching lines @@
     "~followup_annotations": [
       "@@@STEP_TEXT@Syzygy Smoke Test@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]