fix: Use stricter typing and increase psalm level

[come-nc]

todos:

• Relies on [stable33] chore: Remove incorrect resource typing in ILDAPProvider server#59381 being merged and propagated to nextcloud/ocp
• stubs should be updated properly
• Psalm level may be even higher? (lower)
• Rector run
• strict_types everywhere
• strong typing everywhere

[come-nc]

This is already a good improvement, let’s merge this, we can always improve later.