build(wx): move to upstream wxWidgets 3.3.4

Orca pinned the SoftFever fork at branch v3.3.2. That tracks a moving tip and
leaves the 3.3.3 image-decoder buffer overflows unfixed. Build upstream
wxWidgets at tag v3.3.4 instead and carry the fork's one extra commit as an
in-tree patch.

- deps/wxWidgets: GIT_REPOSITORY -> wxWidgets/wxWidgets, GIT_TAG -> v3.3.4
- add 0002-clang-cl-sibling-compiler-prefix.patch (fork PR #7, WIN32 only):
  the generated wxWidgetsConfig.cmake must search the sibling vc_/clang_
  install layout, because cl and clang-cl share an ABI but wx names the
  layout after the compiler that built it
- flatpak: upstream git source, tag v3.3.4, commit 6a42a4b9
- skill: update the pin, add the 3.3.3/3.3.4 sections, re-base the
  changes.txt line citations, and retire the wxGetTranslation() by-value rule
  (3.3.2 returned by value, 3.3.3 reverted to const wxString&)

scripts/flatpak/com.orcaslicer.OrcaSlicer.yml

@@ -118,9 +118,9 @@ modules:
       # Use git instead of archive: wxWidgets 3.3 relies on multiple git
       # submodules (PCRE2, etc.) that are not included in GitHub tarballs.
       - type: git
-        url: https://github.com/SoftFever/Orca-deps-wxWidgets.git
-        tag: orca-3.3.2
-        commit: db1005db3dea2c37a46fb455a9a02e37aa360751
+        url: https://github.com/wxWidgets/wxWidgets.git
+        tag: v3.3.4
+        commit: 6a42a4b999b127cf28a8b5fe686da6b8ca93a9b8
 
   # OrcaSlicer C++ dependencies (built offline with pre-downloaded archives)
   - name: orca_deps