Positioning a \fermata over the last bar line

To position a \fermata sign over the last bar line, you must use a specially modified rehearsal mark.

\version "2.24"

\relative c'' {
  \override Score.RehearsalMark.break-visibility = #begin-of-line-invisible
  c1 \mark \markup { \musicglyph "scripts.ufermata" }
}