Fix copilot-setup-steps: replace reusable workflow with direct steps

[m7pr]

This PR fixes the GitHub Copilot setup workflow by replacing the reusable workflow call with direct steps, as required by GitHub Copilot's limitations for copilot-setup-steps jobs.

Changes:

• Removed uses: insightsengineering/r.pkg.template/.github/workflows/copilot-setup-steps.yaml@main
• Added direct steps for checkout, R setup, and dependency installation
• Uses actions with uses: (which is allowed) instead of reusable workflows (which are not)

This resolves the error: 'Calling a reusable workflow with the uses: keyword is not supported in copilot-setup-steps jobs.'

[github-actions]

Code Coverage Summary

Filename                         Stmts    Miss  Cover    Missing
-----------------------------  -------  ------  -------  -------------
R/qenv-c.R                          55       0  100.00%
R/qenv-class.R                      13       0  100.00%
R/qenv-concat.R                      7       0  100.00%
R/qenv-constructor.R                 1       0  100.00%
R/qenv-errors.R                      4       4  0.00%    6-9
R/qenv-eval_code.R                  60       1  98.33%   40
R/qenv-extract.R                    30       0  100.00%
R/qenv-get_code.R                   24       0  100.00%
R/qenv-get_env.R                     3       1  66.67%   27
R/qenv-get_messages.r                5       0  100.00%
R/qenv-get_outputs.R                 6       0  100.00%
R/qenv-get_var.R                    13       1  92.31%   13
R/qenv-get_warnings.R                5       0  100.00%
R/qenv-join.R                        1       1  0.00%    13
R/qenv-length.R                      2       1  50.00%   2
R/qenv-show.R                       29      29  0.00%    19-50
R/qenv-within.R                      8       0  100.00%
R/utils-get_code_dependency.R      265       3  98.87%   160, 258, 341
R/utils.R                           42       0  100.00%
TOTAL                              573      41  92.84%

Diff against main

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

Results for commit: 9800cd8

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[github-actions]

Unit Tests Summary

  1 files   14 suites   6s ⏱️
186 tests 182 ✅ 4 💤 0 ❌
269 runs  265 ✅ 4 💤 0 ❌

Results for commit 9800cd8.

[github-actions]

Unit Tests Summary

  1 files   14 suites   6s ⏱️
186 tests 182 ✅ 4 💤 0 ❌
269 runs  265 ✅ 4 💤 0 ❌

Results for commit 9800cd8.