ci(workflow): make firmware build manual-only

Author: BenRoe

.github/workflows/build.yml

@@ -2,6 +2,7 @@ on: [push, pull_request, workflow_dispatch]
 
 jobs:
   build:
+    if: github.event_name == 'workflow_dispatch'
     uses: zmkfirmware/zmk/.github/workflows/build-user-config.yml@v0.3.0
 
   draw:
@@ -10,7 +11,7 @@ jobs:
       keymap_patterns: |
         config/felerius_blank_slate.keymap
         config/lpgalaxy_blank_slate.keymap
-      output_folder: "docs/keymaps"
-      destination: "commit"
-      commit_message: "docs: update keymap SVG renders"
+      output_folder: 'docs/keymaps'
+      destination: 'commit'
+      commit_message: 'docs: update keymap SVG renders'
       draw_args: '--ortho-layout {"split": false, "rows": 4, "columns": 12}'