[docs] Add links to recent transparency reports

[kristof.beyls]

Thanks, LGTM.

It would be interesting to have a way to automatically list all reports in the coc-reports directory on this page, rather than maintaining the list manually, so that we don't have to remember to update the explicit list here. But I don't think there is a way to do that...

[cishida]

In D156456#4541413, @kristof.beyls wrote:

Thanks, LGTM.

It would be interesting to have a way to automatically list all reports in the coc-reports directory on this page, rather than maintaining the list manually, so that we don't have to remember to update the explicit list here. But I don't think there is a way to do that...

Agreed! Some sort of trigger or listener would be helpful for this, or any other link that gets pulbished semi-frequently, like Board meeting minutes.

llvm/docs/CodeOfConduct.rst

 * Tanya Lattner (tanyalattner\@llvm.org)
 * Chris Lattner (clattner\@llvm.org)
 * Tom Stellard (tstellar\@llvm.org)
 
 
 Transparency Reports
 ====================
 
+* `July 15, 2023 <https://llvm.org/coc-reports/2023-07-15-report.html>`_
+* `July 15, 2022 <https://llvm.org/coc-reports/2022-07-15-report.html>`_
 * `April 28, 2022 <https://llvm.org/coc-reports/2022-04-28-report.html>`_
 
 For details about what a Transparency Report is and what it contains, please see the :doc:`Response Guide<ResponseGuide>`.
 
 Questions?
 ==========
 
 If you have questions, please feel free to contact the LLVM Foundation Code of