plugins: set currently supported versions

Change-Id: I72483493de56a5d1c030b6d54085128d272bf217
diff --git a/tools/plugins.py b/tools/plugins.py
index 8d88eb9..5238b7f 100644
--- a/tools/plugins.py
+++ b/tools/plugins.py
@@ -20,7 +20,7 @@
 
 
 BRANCHES = ["master"] + [
-    f"stable-{version}" for version in ["3.8", "3.7", "3.6"]
+    f"stable-{version}" for version in ["3.10", "3.9", "3.8"]
 ]
 CI = "https://gerrit-ci.gerritforge.com"
 GERRIT = "https://gerrit-review.googlesource.com"