Move ARM64 Rocky Linux workers into arm64 queue (#2282)

This change also removes the custom setup for the ubuntu2004_arm64
platform that was necessary when we were not running on GCE machines.

It should only be merged once new images with
#2280 have been
deployed.

Progress towards #2272

Author: fweikert

buildkite/bazelci.py

@@ -303,7 +303,7 @@
         "publish_binary": ["linux_arm64"],
         "docker-image": f"gcr.io/{DOCKER_REGISTRY_PREFIX}/rockylinux8",
         "python": "python3.8",
-        "queue": "arm64_v2",  # TODO(#2272): change to arm64
+        "queue": "arm64",
     },
     "rockylinux8_java11": {
         "name": "Rocky Linux 8 (OpenJDK 11, gcc 8.5.0)",
@@ -368,8 +368,6 @@
         "docker-image": f"gcr.io/{DOCKER_REGISTRY_PREFIX}/ubuntu2004",
         "python": "python3.8",
         "queue": "arm64",
-        # TODO(#2272): Re-enable always-pull if we also publish docker containers for Linux ARM64
-        "always-pull": False,
     },
     "kythe_ubuntu2004": {
         "name": "Kythe (Ubuntu 20.04 LTS)",
@@ -1807,10 +1805,6 @@ def remote_caching_flags(platform, accept_cached=True):
     # Only enable caching for untrusted and testing builds, except for trusted MacOS VMs.
     if THIS_IS_TRUSTED and not is_mac():
         return []
-    # We don't enable remote caching on the Linux ARM64 machine since it doesn't have access to GCS.
-    # TODO(#2272): Delete once GCE workers are running.
-    if platform == "ubuntu2004_arm64":
-        return []
 
     platform_cache_key = [
         BUILDKITE_ORG.encode("utf-8"),
@@ -2724,7 +2718,6 @@ def create_step(
             image=PLATFORMS[platform]["docker-image"],
             commands=commands,
             queue=PLATFORMS[platform].get("queue", "default"),
-            always_pull=PLATFORMS[platform].get("always-pull", True),
         )
     else:
         step = {
@@ -2774,7 +2767,7 @@ def create_step(
 
 
 def create_docker_step(
-    label, image, commands=None, additional_env_vars=None, queue="default", always_pull=True
+    label, image, commands=None, additional_env_vars=None, queue="default"
 ):
     env = ["ANDROID_HOME", "ANDROID_NDK_HOME", "BUILDKITE_ARTIFACT_UPLOAD_DESTINATION"]
     if THIS_IS_TRUSTED:
@@ -2789,7 +2782,7 @@ def create_docker_step(
         "agents": {"queue": queue},
         "plugins": {
             "docker#v3.8.0": {
-                "always-pull": always_pull,
+                "always-pull": True,
                 "environment": env,
                 "image": image,
                 "network": "host",