Fix some CI (windows + nasm, core-macro error) (#2676)

* Moves index.html creation until after wasm creation so the webserver doesn't prematurely serve the page
* sets up nasm for windows builds (to be superseded by Remove Dioxus CLI NASM dependency #2666 #2682)
* puts magnanis-cli-support in a blocking task to prevent threadlocking during sequential builds
* changes order of client/server builds such that the client is built before the server so the webserver doesn't prematurely serve invalid client code
* declobbers "serve" such that each project gets a different dir in the target folder
* uses nest_service instead of fallback so the router doesn't respond with fallback codes
* reincorporates doge's fix from Fix hot-reloading on Windows #2544

packages/core-macro/tests/rsx/trailing-comma-0.stderr

@@ -1,7 +1,6 @@
 error: Attributes must be separated by commas
+       = help: Did you forget a comma?
  --> tests/rsx/trailing-comma-0.rs:9:13
   |
 9 |             class: "foo bar"
   |             ^^^^^
-  |
-  = help: Did you forget a comma?