Roll Flutter Engine from bb2a903c934c to 791f505c8c6e (4 revisions) (#131645)

https://github.com/flutter/engine/compare/bb2a903c934c...791f505c8c6e

2023-08-01 skia-flutter-autoroll@skia.org Roll Skia from 2e5f08012a92 to 177897b13a89 (1 revision) (flutter/engine#44199)
2023-08-01 skia-flutter-autoroll@skia.org Roll ANGLE from cb4b1f3641ae to 6dc0c9d62755 (2 revisions) (flutter/engine#44198)
2023-08-01 chinmaygarde@google.com [Impeller] Document the fiddly bits about setting up Metal shader source debugging. (flutter/engine#44195)
2023-07-31 chinmaygarde@google.com [Impeller] Add documentation on how to enable Metal Profiling HUD without Xcode. (flutter/engine#44196)

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/flutter-engine-flutter-autoroll
Please CC jonahwilliams@google.com,rmistry@google.com,zra@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://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

bin/internal/engine.version

-bb2a903c934cc800c9d4c6649e3acf863fee5436
+791f505c8c6e7d9a53671606f1bbd906c8ddf7f0