Add WSL Woodpecker cross-build test and prefer bundled headers

.woodpecker.yml

@@ -0,0 +1,23 @@
+when:
+  - event: [push, manual]
+    branch: skia3
+
+labels:
+  platform: linux/amd64
+  backend: local
+
+clone:
+  skip: true
+
+steps:
+  - name: checkout
+    image: bash
+    commands:
+      - git init source
+      - git -C source remote add origin https://git.oeo.one/greepar/StaticLink.Avalonia.git
+      - git -C source fetch --depth=1 origin "$CI_COMMIT_SHA"
+      - git -C source checkout --detach FETCH_HEAD
+  - name: environment-and-linux-x64
+    image: bash
+    commands:
+      - bash source/scripts/woodpecker-cross-test.sh