Auto merge of #23863 - jdm:gstreamer-uwp, r=ferjm

Various UWP GStreamer improvements

There are a number of positive changes in these commits:
* we successfully load GStreamer plugins in ARM64 UWP builds
* we correctly link the ARM64 ANGLE libraries when appropriate
* it is no longer necessary to manually set the LIB environment variable on Windows
* we automatically download and link against UWP-friendly GStreamer binaries when building with `--uwp`
* the use of vcruntime140.dll, msvcp140.dll and api-ms-win-crt-runtime-l1-1-0.dll in the UWP application has been removed and the build does not repackage them
* the set of base supporting GStreamer DLLs has been expanded to allow the gstlibav plugin to load correctly

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #23742
- [x] There are tests for these changes

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/23863)
<!-- Reviewable:end -->

1 files changed, 1 insertions, 0 deletions

diff --git a/python/servo/packages.py b/python/servo/packages.py
index 2d10156ad22..3fa2f036fb8 100644
--- a/python/servo/packages.py
+++ b/python/servo/packages.py
@@ -8,4 +8,5 @@ WINDOWS_MSVC = {
     "moztools": "3.2",
     "ninja": "1.7.1",
     "openssl": "111.3.0+1.1.1c-vs2017",
+    "gstreamer-uwp": "1.16.0.3",
 }