Add concurrency settings to mkdocs-deploy workflow

Signed-off-by: Hunter T. <strangeranger@hthompson.dev>

Author: StrangeRanger

.github/workflows/mkdocs-deploy.yml

@@ -8,6 +8,10 @@ on:
 permissions:
   contents: read
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     runs-on: ubuntu-latest