QSvgFont: Mark glyph containers private


m_glyphs was used by qtdeclrative but that
was already fixed in the 6.10 branch.

Pick-to: 6.12 6.11
Change-Id: I11ad1b25059cdef135931e76a365e8d142c88f30
Reviewed-by: Hatem ElKharashy <hatem.elkharashy@qt.io>
commitbbbb97aaf2c76666c95045a282d4e72ad68bc5c5
parent4bfc4ccd683d3d79133cf8a936e7457bff440d6b
authorRobert Löhning <robert.loehning@qt.io>
committerRobert Löhning <robert.loehning@qt.io>
commit timeTue, 25 Aug 2026 07:50:20 +0000