feat(cli): add --no-wait flag to coder create (#22867)

Adds a `--no-wait` flag (CODER_CREATE_NO_WAIT) to the create command,
matching the existing pattern in `coder start`. When set, the `coder
create` command returns immediately after the workspace creation API
call succeeds instead of streaming build logs until completion.

This enables fire-and-forget workspace creation in CI/automation
contexts (e.g., GitHub Actions), where waiting for the build to finish
is unnecessary. Combined with other existing flags, users can create a
workspace with no interactivity, assuming the user is already
authenticated.

cli/testdata/coder_create_--help.golden

@@ -20,6 +20,10 @@ OPTIONS:
       --copy-parameters-from string, $CODER_WORKSPACE_COPY_PARAMETERS_FROM
           Specify the source workspace name to copy parameters from.
 
+      --no-wait bool, $CODER_CREATE_NO_WAIT
+          Return immediately after creating the workspace. The build will run in
+          the background.
+
       --parameter string-array, $CODER_RICH_PARAMETER
           Rich parameter value in the format "name=value".