Allow multiple calls with different tools

[alexeyr-ci2]

I have both smallerIsBetter and largerIsBetter benchmarks (latencies and RPS). However, when I tried to use the action twice in a workflow, the second one failed with

/usr/bin/git -c user.name=github-action-benchmark -c user.email=github@users.noreply.github.com -c http.https://github.com/.extraheader= fetch ***github.com/shakacode/react_on_rails.git benchmark-data:benchmark-data
From https://github.com/shakacode/react_on_rails
 ! [rejected]        benchmark-data -> benchmark-data  (non-fast-forward)
Error: Command 'git' failed with args '-c user.name=github-action-benchmark -c user.email=github@users.noreply.github.com -c http.https://github.com/.extraheader= fetch ***github.com/shakacode/react_on_rails.git benchmark-data:benchmark-data': From https://github.com/shakacode/react_on_rails
 ! [rejected]        benchmark-data -> benchmark-data  (non-fast-forward)
: Error: The process '/usr/bin/git' failed with exit code 1

(you can see the run here and the corresponding workflow here; it actually has 4 uses, but 2 pairs could be merged. For now I'll work around by using -RPS, but is there a better way?