This PR adds the linux and windows target platform enum values, along with automatically setting the defaultTargetPlatform to the appropriate value on those platforms.

Fixes #31366

* 38f497c4d Roll src/third_party/skia 9dd0bd78b2d7..470f0637aeea (11 commits) (flutter/engine#16887)

* 5073cc7cb Roll src/third_party/dart fbe9f6115d2f..0b819161d778 (3 commits) (flutter/engine#16888)

* df942131b Revert "Try rasterizing images and layers only once , even when their rasterization fails. Further enforce the same access threshold on layers as on Pictures. Previously layers would always be cached. The latter is a semantic change. (#16545)" (flutter/engine#16889)

* b230adbb3 Roll src/third_party/skia 470f0637aeea..ded437003d0e (6 commits) (flutter/engine#16891)

* 63bdf3e1b Roll fuchsia/sdk/core/mac-amd64 from q2DAy... to WmA2M... (flutter/engine#16892)

* e54f2c8c1 Const finder missing `static const` list/map/set fields. (flutter/engine#16896)

* 10275fe66 Roll fuchsia/sdk/core/linux-amd64 from 9NHsJ... to uiAI5... (flutter/engine#16893)

* 8d046faf9 Roll src/third_party/skia ded437003d0e..b43cfa4d3f96 (7 commits) (flutter/engine#16894)

* 9c5399315 Roll src/third_party/dart 0b819161d778..ca3ad264a649 (18 commits) (flutter/engine#16898)

* 6991dd981 Roll src/third_party/skia b43cfa4d3f96..8121d27b297c (10 commits) (flutter/engine#16899)

* 9beac71a2 Add support for software text editing controls (flutter/engine#15560)

* ab9f83fe0 Roll fuchsia/sdk/core/linux-amd64 from RYDur... to bgFop... (flutter/engine#16855)

* 62d0c0829 Roll src/third_party/dart dda5bcee00d3..4dad6d77ba50 (6 commits) (flutter/engine#16856)

* 76d12d2cb Roll src/third_party/skia 03d9e8af0d25..262796edeba6 (11 commits) (flutter/engine#16857)

* 01a52b994 Try rasterizing images and layers only once, even when their rasterization fails. Further enforce the same access threshold on layers as on Pictures. Previously layers would always be cached. The latter is a semantic change. (flutter/engine#16545)

* 3b0d1a8d2 script for fetching correct flutter version (flutter/engine#16818)

* 9746ddb61 Roll src/third_party/dart 4dad6d77ba50..6708f6d4c7df (15 commits) (flutter/engine#16860)

* 90736bbc5 Roll src/third_party/skia 262796edeba6..54cb21430ccb (23 commits) (flutter/engine#16861)

* 142882e1b Roll src/third_party/skia 54cb21430ccb..e1ae9c4bcf2e (4 commits) (flutter/engine#16863)

* 71923563a Manual roll of Dart 09bbd3cca5...6708f6d4c7 (flutter/engine#16864)

* fae5ff658 Roll src/third_party/skia e1ae9c4bcf2e..5d1c3e2ead61 (2 commits) (flutter/engine#16865)

* c6525a428 Roll src/third_party/skia 5d1c3e2ead61..59b160f99106 (2 commits) (flutter/engine#16866)

* 755e2b559 Roll src/third_party/skia 59b160f99106..71a20b2685c6 (1 commits) (flutter/engine#16867)

* 93d0eff4d Roll src/third_party/skia 71a20b2685c6..ecbb0fb2d5bc (1 commits) (flutter/engine#16869)

* bfee5ae23 Roll fuchsia/sdk/core/linux-amd64 from bgFop... to F_Ihm... (flutter/engine#16871)

* ca29b47bf Roll fuchsia/sdk/core/mac-amd64 from K26F5... to 79I0C... (flutter/engine#16872)

* 708ca2c62 Roll src/third_party/skia ecbb0fb2d5bc..666707336e07 (1 commits) (flutter/engine#16873)

* 78ea291da Roll fuchsia/sdk/core/mac-amd64 from 79I0C... to NoQzJ... (flutter/engine#16874)

* 7b43bb863 Roll fuchsia/sdk/core/linux-amd64 from F_Ihm... to 22R78... (flutter/engine#16875)

* 75c9c62f8 Roll src/third_party/skia 666707336e07..231f1bf56556 (1 commits) (flutter/engine#16876)

* 7a86b83f0 Roll src/third_party/dart 09bbd3cca5d4..860dca93ea42 (1 commits) (flutter/engine#16877)

* d0c87e212 Roll src/third_party/skia 231f1bf56556..d6205322cdc5 (1 commits) (flutter/engine#16878)

* b4c58545a Roll src/third_party/skia d6205322cdc5..6729496a037f (1 commits) (flutter/engine#16879)

* 03f0ee548 Roll src/third_party/skia 6729496a037f..367dbff98555 (1 commits) (flutter/engine#16880)

* d84b96855 Roll fuchsia/sdk/core/mac-amd64 from NoQzJ... to q2DAy... (flutter/engine#16881)

* 4490e7cf9 Roll fuchsia/sdk/core/linux-amd64 from 22R78... to 9NHsJ... (flutter/engine#16882)

* a39e7ac44 Roll src/third_party/skia 367dbff98555..986680240f81 (1 commits) (flutter/engine#16884)

* 62b1e50ed Roll src/third_party/dart 860dca93ea42..fbe9f6115d2f (9 commits) (flutter/engine#16885)

* 5e474ee86 Roll src/third_party/skia 986680240f81..9dd0bd78b2d7 (2 commits) (flutter/engine#16886)

* Revert #51693
* Revert #51689

https://github.com/flutter/flutter/issues/51776

* Fix doc typo

The original commit actually *enabled* the test by removing the
flaky: true field in the commit.

This reverts commit 1d3fcfd6.

This reverts commit 9375377f.

Fixes #51511

* add docs about writing/running web benchmarks

* explain how to run like devicelab

* add WidgetBuildRecorder docs

This reverts commit 2132a0c7.

Use strut box heights to calculate selection rectangles in order to ensure that they remain within visible bounds (#50354)

This reverts commit 9de7787f.