Update Test Images

[plengauer]

(this PR is automatically generated)

[Copilot]

Pull request overview

Updates the Ubuntu container tags used by CI/test matrix generation via .github/images.json.

Changes:

• Bumps Ubuntu stable to ubuntu:questing and latest to ubuntu:resolute.
• Sets Ubuntu dev to an empty-tag image reference (ubuntu:).

[plengauer]

@copilot analyze the check errors and fix it

[Copilot]

@copilot analyze the check errors and fix it

Fixed in commit 4f880e8. The CI failures on ubuntu:resolute (Ubuntu 26.04) were caused by rev not being available on that image. I replaced all rev-based idioms with POSIX-compliant alternatives:

• test_sdk_observe.sh: which cat | rev | cut -d ' ' -f 1 | rev → which cat | awk '{print $NF}'
• assert.sh (assert_ends_with): replaced rev-based suffix check with shell case pattern matching
• Three auto-injection tests: readlink ... | rev | cut -d / -f 1 | rev → basename "$(readlink ...)"
• images.json: fixed ubuntu.dev from invalid ubuntu:stonking to ubuntu:devel