Revert "Turn on concurrent set deletions in sweep thread" #9597

Job	Run time
make (yjit-bindgen, To fix: use patch in logs, --with-gcc=clang-14 --enable-yjit=dev --enable-zji...	5m 21s
make (check, RUSTC='rustc +1.58.0', 1.58.0)	4m 41s
make (check, --enable-yjit=dev, --yjit-call-threshold=1 --yjit-verify-ctx --yjit-code-gc, -T --yj...	5m 30s
cargo clippy	35s
cargo test	42s
make (check, --enable-yjit=dev)	5m 25s
make (test-bundled-gems, --enable-yjit=dev)	23m 58s
YJIT Ubuntu result	4s
	46m 16s

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