Fix dropdown

Author: thopkins32

.github/workflows/_docs.yml

@@ -16,6 +16,7 @@ jobs:
         run: |
           export REPOSITORY_NAME=${GITHUB_REPOSITORY#*/}  # just the repo, as opposed to org/repo
           echo "REPOSITORY_NAME=${REPOSITORY_NAME}" >> $GITHUB_ENV
+          echo "DOCS_VERSION=${GITHUB_REF_NAME//[^A-Za-z0-9._-]/_}" >> $GITHUB_ENV
 
       - name: Checkout the code
         uses: actions/checkout@v5
@@ -42,9 +43,6 @@ jobs:
           name: ${{ env.REPOSITORY_NAME }}-docs
           path: docs/build/html/
 
-      - name: Sanitize ref name for docs version
-        run: echo "DOCS_VERSION=${GITHUB_REF_NAME//[^A-Za-z0-9._-]/_}" >> $GITHUB_ENV
-
       - name: Move to versioned directory
         run: mv docs/build/html .github/pages/$DOCS_VERSION
 

docs/source/conf.py

@@ -147,7 +147,7 @@
 html_theme_options = {
     "switcher": {
         "json_url": "https://bluesky.github.io/blop/switcher.json",
-        "version_match": version,
+        "version_match": os.environ.get("DOCS_VERSION", "main"),
     },
     "navbar_end": ["version-switcher", "theme-switcher", "navbar-icon-links"],
 }