Roll Packages from 38711ac to b21c542 (5 revisions) (#145152)

flutter/packages@38711ac...b21c542

2024-03-14 pageli328@gmail.com Support overriding `ErrorWidget.builder` (flutter#6302)
2024-03-13 engine-flutter-autoroll@skia.org Manual roll Flutter from 61812ca to 394269f (6 revisions) (flutter#6320)
2024-03-13 49699333+dependabot[bot]@users.noreply.github.com Bump actions/checkout from 4.1.1 to 4.1.2 (flutter#6309)
2024-03-13 magder@google.com Replace deprecated UIGraphicsBeginImageContextWithOptions with UIGraphicsImageRenderer (flutter#6285)
2024-03-13 49699333+dependabot[bot]@users.noreply.github.com Bump github/codeql-action from 3.24.6 to 3.24.7 (flutter#6310)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-packages-flutter-autoroll
Please CC flutter-ecosystem@google.com,rmistry@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

bin/internal/flutter_packages.version

@@ -1 +1 @@
-38711aca66fa91cff1815839f99e9819f3c27d60
+b21c5424783a9e74cb841a8df7a15f26eba04a7b