repo: move compnerd/swift-build to gha-ci

This moves the checkout location for the `//swift/build` project to
`gha-ci` to accommodate the overlapping `swift-build` project from
Swift.

Author: compnerd

default.xml

@@ -47,7 +47,7 @@
   <project remote="github" name="apple/swift-xcode-playground-support" path="swift-xcode-playground-support" groups="notdefault" />
 
   <project remote="github" name="compnerd/ds2" path="ds2" />
-  <project remote="github" name="compnerd/swift-build" path="swift-build" />
+  <project remote="github" name="compnerd/swift-build" path="gha-ci" />
   <project remote="github" name="compnerd/swift-win32" path="swift-win32" />
 
   <project remote="github" name="curl/curl" path="curl" revision="refs/tags/curl-8_9_1" />