Add approval blocking labels for new bors

Author: Kobzol

rust-bors.toml

@@ -1,2 +1,19 @@
 # 6 hours timeout for CI builds
 timeout = 21600
+
+# Do not allow approving PRs with certain labels
+labels_blocking_approval = [
+    # Waiting for an FCP to finish
+    "final-comment-period",
+    "proposed-final-comment-period",
+    # PRs that were closed or postponed by an FCP
+    "disposition-close",
+    "disposition-postpone",
+    # Waiting for library ACP
+    "S-waiting-on-ACP",
+    "S-waiting-on-concerns",
+    "S-waiting-on-crater",
+    "S-waiting-on-fcp",
+    "S-waiting-on-MCP",
+    "S-waiting-on-team"
+]