Disable clippy on Cirrus for now

Author: k0kubun

.cirrus.yml

@@ -106,4 +106,5 @@ yjit_task:
   make_test_script: make test RUN_OPTS="--yjit-call-threshold=1 --yjit-verify-ctx"
   make_test_all_script: make test-all RUN_OPTS="--yjit-call-threshold=1 --yjit-verify-ctx" TESTOPTS="$RUBY_TESTOPTS"
   make_test_spec_script: make test-spec RUN_OPTS="--yjit-call-threshold=1 --yjit-verify-ctx"
-  clippy_script: cd yjit && rustup component add clippy && cargo clippy --all-targets --all-features
+  # Cirrus Rust environments don't have enough permission to run `rustup component add clippy`.
+  # clippy_script: cd yjit && rustup component add clippy && cargo clippy --all-targets --all-features