[attribute form] Insure that a field features multiple times in a feature form has its constraint properly reflected

[nirvn]

Description

This PR fixes #55607 , whereas a feature form featuring the same field editor widget multiple times would not have their constraints properly reflected in the UI.

[github-actions]

🪟 Windows builds ready!

Windows builds of this PR are available for testing here. Debug symbols for this build are available here.

(Built from commit 55fb32e)

[3nids]

nice!

[qgis-bot]

The backport to release-3_34 failed:

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

stderr

error: could not apply 9f3df359246... [attribute form] Insure that a field features multiple times in a feature form has its constraint properly reflected
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".

stdout

CONFLICT (modify/delete): python/PyQt6/gui/auto_generated/editorwidgets/core/qgseditorwidgetwrapper.sip.in deleted in HEAD and modified in 9f3df359246 ([attribute form] Insure that a field features multiple times in a feature form has its constraint properly reflected).  Version 9f3df359246 ([attribute form] Insure that a field features multiple times in a feature form has its constraint properly reflected) of python/PyQt6/gui/auto_generated/editorwidgets/core/qgseditorwidgetwrapper.sip.in left in tree.

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_34 release-3_34
# Navigate to the new working tree
cd .worktrees/backport-release-3_34
# Create a new branch
git switch --create backport-56163-to-release-3_34
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 9f3df3592466ac2163eeeab2d2770fdb2b1fb94f,55fb32e9ed6bd627ab3e9a917b33a9623d0ec25e
# Push it to GitHub
git push --set-upstream origin backport-56163-to-release-3_34
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release-3_34

Then, create a pull request where the base branch is release-3_34 and the compare/head branch is backport-56163-to-release-3_34.