[MacPorts] #66975: qt6: Update to 6.4

[MacPorts]

#66975: qt6: Update to 6.4
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  Reporter:  MaddTheSane  |      Owner:  (none)
      Type:  update       |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.8.1
Resolution:               |   Keywords:
      Port:  qt6          |
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Comment (by jhoyt4):

 Qt 6.5 LTS releases at the end of March
 [https://wiki.qt.io/Qt_6.5_Release]

 That version seemed like the natural next version to upgrade to when
 released [https://endoflife.date/qt]

 ...at least that was my plan unless someone else gets to it first.

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Ticket URL: <https://trac.macports.org/ticket/66975#comment:2>
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