Omitting an accidental

[David Sumbler]

I am having difficulty with the new repeat structure.  The code below
produces the result I want except that the repeat should only be 2 bars
long.  In other words, the ":|." bar line at the end of the inner
repeat should come at the end of the 1st time bar (after the note F)
not 2 bars later after the A.

\version "2.24.3"
\language "english"

\score {
  \repeat segno 2 {
    c'1 d'
    \fine
    \volta 2

    \volta 1 {
      \repeat volta 2 {
        e'1
        \alternative {
          \volta 1 { f'1 }
          \volta 2 { g'1 }
        }
        a'1
      }
    }
  }
}

I have tried omitting  the inner "\volta 1" and "\volta 2",
corresponding to another example in Notation Ref. 1.4.1, but I get
exactly the same result.

Can somebody explain what I am doing wrong?

David