feat: Add GitLab CI conf

[cicdguy]

Add GitLab CI conf.

Also remove exec permissions from various files.

[github-actions]

✅ All contributors have signed the CLA
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[cicdguy]

I have read the CLA Document and I hereby sign the CLA

[github-actions]

Code Coverage Summary

Filename                  Stmts    Miss  Cover    Missing
----------------------  -------  ------  -------  ------------------------------------------------------------------------------------------
R/assert.R                   26      25  3.85%    2, 7-43
R/autoslideR_error.R          7       0  100.00%
R/decorate.R                138      96  30.43%   9, 47, 82-154, 180, 224-303
R/fastdocall.R               28      28  0.00%    14-51
R/format_date.R               9       9  0.00%    33-42
R/ft_formats.R               54      54  0.00%    30-163
R/func_wrapper.R             36      36  0.00%    9-50
R/generate_output.R          57      57  0.00%    40-135
R/helper_functions.R         36      20  44.44%   16-20, 63-80
R/log.R                      31      13  58.06%   26-39
R/null_report.R               4       0  100.00%
R/package.R                   1       1  0.00%    72
R/save_output.R              58      55  5.17%    34-42, 60-185
R/spec.R                     60      60  0.00%    30-159
R/t_ae_slide.R               74      74  0.00%    25-111
R/t_ae_summary_slide.R      154     154  0.00%    57-240
R/t_aesi_slide.R            132     132  0.00%    24-172
R/t_dd_slide.R               23       0  100.00%
R/t_dm_slide.R               32       0  100.00%
R/t_dor_slide.R              65       0  100.00%
R/to_ft_funs.R              221     221  0.00%    5-447
R/to_slides.R               142     142  0.00%    50-318
R/util.R                    300     218  27.33%   12-22, 54, 69, 80-125, 182-275, 301-313, 319, 343, 351-446, 457-509, 525-531, 535, 548-575
TOTAL                      1688    1395  17.36%

Diff against main

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

Results for commit: 8b952d0

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[github-actions]

Unit Tests Summary

 1 files   8 suites   2s ⏱️
13 tests  6 ✅ 7 💤 0 ❌
36 runs  27 ✅ 9 💤 0 ❌

Results for commit 8b952d0.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Performance Difference

Test Suite	$Status$	Time on main	$±Time$	$±Tests$	$±Skipped$	$±Failures$	$±Errors$
t_dm_slide	💔	$0.35$	$+1.26$	$+4$	$-1$	$0$	$0$

Additional test case details

Test Suite	$Status$	Time on main	$±Time$	Test Case
t_dm_slide	💔	$0.35$	$+1.26$	Test_demographic_table_creation_of_t_dm_slide

Results for commit 5b4ed95

♻️ This comment has been updated with latest results.

[shajoezhu]

lgtm! thanks @cicdguy approve to unblock merge