fix(settings): Increase "Edit your profile visibility button" contrast

[susnux]

• Resolves: [BITV] 9.1.4.3/6.2 - The "Edit your Profile visibility" link does not meet the contrast requirements for text - it is 2.4:1. (1) #36958

Summary

Rather a very small fix, but before this the contrast of the button was too low in terms of accessibility.

Screenshots

state	inactive	hover
before
after

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Screenshots before/after for front-end changes
• Backports requested where applicable (ex: critical bugfixes)

[susnux]

/backport to stable26

[Pytal]

/compile amend /

[szaimen]

LGTM but didnt test

[backportbot-nextcloud]

The backport to stable26 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable26
git pull origin/stable26

# Create the new backport branch
git checkout -b fix/foo-stable26

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable26

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport