Set LANG: en_US.UTF-8 to fix locale issue in rocker

[cicdguy]

See r-lib/styler#1199 and rocker-org/rocker-versioned2#802 for reference.

This adds the LANG=en_US.UTF-8 environment variable in the event that it is not set.

[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: 4f1082f

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 4f1082f.