ci: Skip cloning no longer used rustc-timing repo

Author: Mark-Simulacrum

ci/check-benchmarks.sh

@@ -5,7 +5,6 @@ set -x;
 bash -c "while true; do sleep 30; echo \$(date) - running ...; done" &
 PING_LOOP_PID=$!
 trap - ERR
-git clone https://github.com/rust-lang/rustc-timing.git;
 cargo build -p collector;
 RUST_BACKTRACE=1 RUST_LOG=collector=trace,rust_sysroot=debug \
     cargo run -p collector --bin collector -- \