[TASK] Update login page screenshot

[brotkrueml]

Previously, this screenshot has been generated automatically. But as the
Screenshot Tool is not working anymore in newer TYPO3 versions, the image
has been moved to the "ManualScreenshots" folder.

Releases: main, 12.4

[github-actions]

The backport to 12.4 failed:

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

stderr

error: could not apply d422a8a... [TASK] Update login page screenshot
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): Documentation/Localization.ru_RU/Login/Index.rst deleted in HEAD and modified in d422a8a ([TASK] Update login page screenshot).  Version d422a8a ([TASK] Update login page screenshot) of Documentation/Localization.ru_RU/Login/Index.rst left in tree.
CONFLICT (modify/delete): Documentation/Localization.ru_RU/screenshots.json deleted in HEAD and modified in d422a8a ([TASK] Update login page screenshot).  Version d422a8a ([TASK] Update login page screenshot) of Documentation/Localization.ru_RU/screenshots.json 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-12.4 12.4
# Navigate to the new working tree
cd .worktrees/backport-12.4
# Create a new branch
git switch --create backport-142-to-12.4
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick d422a8a7aa367aa24b7a5e8aab74b9d829fbc45f
# Push it to GitHub
git push --set-upstream origin backport-142-to-12.4
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-12.4

Then, create a pull request where the base branch is 12.4 and the compare/head branch is backport-142-to-12.4.