Add remote server cross compilation (#19136)

This will allow us to compile debug builds of the remote-server for a
different architecture than the one we are developing on.

This also adds a CI step for building our remote server with minimal
dependencies.

Release Notes:

- N/A

Dockerfile-cross.dockerignore

@@ -0,0 +1,16 @@
+.git
+.github
+**/.gitignore
+**/.gitkeep
+.gitattributes
+.mailmap
+**/target
+zed.xcworkspace
+.DS_Store
+compose.yml
+plugins/bin
+script/node_modules
+styles/node_modules
+crates/collab/static/styles.css
+vendor/bin
+assets/themes/