ci: pin gh action to v2_k7_1_6_3 to resolve build errors

[pasrom]

Fixed a build error by specifying the version of a GitHub Action to v2_k7_1_6_3. This addresses an issue where the command git worktree add --detach --force /tmp/tmpy_4q2jth main failed. The error was resolved by using v2_k7_1_6_3 until the changes in commit https://github.com/INTI-CMNB/KiBot/commit/d66188014c67307d9820ad9a72239d624488c446 are included in the LTS tag v2_k7. Following the resolution of issue https://github.com/INTI-CMNB/KiBot/issues/589, it will then be necessary to change main to origin/main in diff.kibot.yaml.

[github-actions[bot]]

Diff between main (3bd7b67) and fix-ci (25a5562):

• bms-c1-diff_sch.pdf
• bms-c1-diff_pcb.pdf