synapse workers: make awk script invocation handle paths with spaces

(quoting ftw)

roles/matrix-synapse/tasks/workers/setup_install.yml

@@ -7,7 +7,7 @@
 
 - name: Download synapse workers doc and convert into YAML
   shell:
-    cmd: "awk -f {{ role_path }}/files/workers-doc-to-yaml.awk -- {{ role_path }}/files/workers.upstream-documentation.md > {{ role_path }}/vars/workers.yml"
+    cmd: "awk -f '{{ role_path }}/files/workers-doc-to-yaml.awk' -- '{{ role_path }}/files/workers.upstream-documentation.md' > '{{ role_path }}/vars/workers.yml'"
     creates: "{{ role_path }}/vars/workers.yml"
 
 - name: Load list of available worker apps and endpoints