pw_env_setup: Drop compatibility with old arm-gcc

Change-Id: I2824174022a7d4b9a63e510bac76ce57693b11a7
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/110670
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Armando Montanez <amontanez@google.com>
diff --git a/pw_env_setup/py/pw_env_setup/cipd_setup/compatibility.json b/pw_env_setup/py/pw_env_setup/cipd_setup/compatibility.json
index 97150cf..ddbcdac 100644
--- a/pw_env_setup/py/pw_env_setup/cipd_setup/compatibility.json
+++ b/pw_env_setup/py/pw_env_setup/cipd_setup/compatibility.json
@@ -12,17 +12,6 @@
       "tags": [
 	"version:2@3.8.10.chromium.24"
       ]
-    },
-    {
-      "path": "pigweed/third_party/gcc-arm-none-eabi/${platform}",
-      "platforms": [
-        "linux-amd64",
-        "mac-amd64",
-        "windows-amd64"
-      ],
-      "tags": [
-        "version:9-2020-q2-update"
-      ]
     }
   ]
 }