Fix regression introduced by #58755

[benwirf]

Description

This PR fixes a regression introduced by a previous PR of mine #58755 which broke snapping in non feature digitizing tools e.g. annotation digitizing tools if there was no active layer or active layer was not spatial. This approach also still addresses the original bug report from #56152.

[3nids]

great, it looks better than the fix I have here https://github.com/qgis/QGIS/pull/60156/commits
But I have added a test case ff1a7e0
You cherry-pick it so we can backport?

[github-actions]

🪟 Windows builds

Download Windows builds of this PR for testing.
Debug symbols for this build are available here.
(Built from commit f69e767)

🪟 Windows Qt6 builds

Download Windows Qt6 builds of this PR for testing.
(Built from commit f69e767)

[benwirf]

Thanks @3nids. I'm happy to try that, though I'm afraid my git knowledge is fairly basic! Do I just do: git cherry-pick ff1a7e0 on my branch, then commit & push?

[3nids]

git remote add 3nids git@github.com:3nids/QGIS.git
git fetch 3nids
git cherry-pick ff1a7e0
git push

should do the job (cherry-pick also commits)
you have to add my repo first since the commit is on my fork

[benwirf]

@3nids, great, thanks! I'm away from my computer for a couple of hours; I will try it as soon as I get back.
Cheers

[3nids]

I've just pushed, so I can move forward on the other one

[benwirf]

@3nids, thank you- much appreciated. Sorry for the trouble.

[3nids]

no worries, thanks for the reactivity!