Fix value relation editor widget serious warnings

[nirvn]

Spotted while fixing #5397

Less warnings == better world. In this case, I think the warnings were indicating a possible scenario in which we get our model wires crossed.

Possibly fixing #5374

[qfield-fairy]

🎉 Ta-daaa, freshly created APKs are available for ca3bf32: arm64-android

Other architectures

• arm-neon-android
• x64-android
• x86-android
• all access arm64-android
• all access arm-neon-android
• all access x64-android
• all access x86-android

[qfield-fairy]

The backport to release-3_3 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply ca3bf32bc... Fix value relation editor widget serious warnings
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config advice.mergeConflict false"

stdout

Auto-merging src/core/featurechecklistmodel.cpp
Auto-merging src/core/featurechecklistmodel.h
CONFLICT (content): Merge conflict in src/core/featurechecklistmodel.h

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release-3_3 release-3_3
# Navigate to the new working tree
cd .worktrees/backport-release-3_3
# Create a new branch
git switch --create backport-5399-to-release-3_3
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick ca3bf32bcdc4fc30cd5f8c3920a0bb679b6cb9f1
# Push it to GitHub
git push --set-upstream origin backport-5399-to-release-3_3
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release-3_3

Then, create a pull request where the base branch is release-3_3 and the compare/head branch is backport-5399-to-release-3_3.