Add concurrency group input to R CMD check workflow

[walkowif]

Add concurrency group input to allow multiple simultaneous instances of R CMD check workflow in a calling workflow (utilized e.g. in TLG Catalog).

[pawelru]

Thank you!

[github-actions]

Code Coverage Summary

Filename      Stmts    Miss  Cover    Missing
----------  -------  ------  -------  ---------
R/hello.R        20       6  70.00%   55-60
TOTAL            20       6  70.00%

Diff against main

Filename      Stmts    Miss  Cover
----------  -------  ------  --------
TOTAL             0       0  +100.00%

Results for commit: 5fec3df

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[github-actions]

Unit Tests Summary

3 tests   3 ✅  6s ⏱️
3 suites  0 💤
1 files    0 ❌

Results for commit 5fec3df.