Fix NUKE_CERT variables to be case insensitive in bash

[bjorkert]

Summary

• Use ${VAR,,} bash parameter expansion for case-insensitive comparisons instead of introducing _LC helper variables (supersedes make the NUKE_CERT variables case insensitive #528)
• Fix bug where FORCE_NUKE_CERTS was compared as the literal string vars.FORCE_NUKE_CERTS instead of the actual variable value
• Add missing FORCE_NUKE_CERTS=${{ vars.FORCE_NUKE_CERTS }} assignment so bash has access to the variable
• No changes to the nuke_certs job if: condition since GitHub Actions == is already case-insensitive

Test plan

• Set ENABLE_NUKE_CERTS to True, TRUE, and true — all should be recognized
• Set FORCE_NUKE_CERTS to True, TRUE, and true — all should trigger the force warning annotation
• Set FORCE_NUKE_CERTS to false or unset — no force warning annotation
• Verify the nuke_certs job still triggers correctly based on the GitHub Actions if: expression

[marionbarker]

Test

Push this branch to my docs-test organization.

Test FORCE_NUKE_CERTS failed

set FORCE_NUKE_CERTS to "TRUE"

• ❌ create_certs failed to run
• https://github.com/docs-test/LoopFollow/actions/runs/23161438548/job/67290091684#step:7:41

line 16: ${ENABLE_NUKE_CERTS,,}: bad substitution

[marionbarker]

Comment on prior test:

The previous version used bash 4+ syntax and macos runners use bash 3.2.

Most recent commit uses syntax suitable for bash 3.2

Test

✅ successful tests

Ignore the Node.js.20 warnings. Those don't matter until Jun 2026 and they will be updated with a different PR when the tools are available.

Push this branch to my docs-test organization.

Test FORCE_NUKE_CERTS

set FORCE_NUKE_CERTS to "TRUE"
set ENABLE_NUKE_CERTS to "True"

• ✅ create_certs succeeded and force the certificate
• https://github.com/docs-test/LoopFollow/actions/runs/23162235614

Test ENABLE_NUKE_CERTS

valid certs test

set FORCE_NUKE_CERTS to "False"
leave ENABLE_NUKE_CERTS to "True"

• ✅ create_certs succeeded - recognized certs exist and are valid
• https://github.com/docs-test/LoopFollow/actions/runs/23162537347

invalid certs test

Delete my distribution certificate

• ✅ build LoopFollow succeeded - recognized certs were needed and obtained them, successful build
• https://github.com/docs-test/LoopFollow/actions/runs/23162615039

[marionbarker]

Approved by code review and test.