Add experimental functionality for labelling PRs by their size #1624

Job	Run time
Rust analysis (ubuntu-latest, stable-v2.22.1)	1m 51s
Rust analysis (ubuntu-latest, default)	1m 35s
Rust analysis (ubuntu-latest, stable-v2.19.3)	1m 13s
Rust analysis (ubuntu-latest, nightly-latest)	1m 38s
Rust analysis (ubuntu-latest, linked)	1m 41s
	7m 58s

Provide feedback