workflow: quote version bound

Author: alcarney

.github/workflows/lsp-release.yml

@@ -31,7 +31,7 @@ jobs:
 
         python --version
         python -m pip install --upgrade pip
-        python -m pip install --upgrade tox bump2version towncrier docutils<0.21
+        python -m pip install --upgrade tox bump2version towncrier 'docutils<0.21'
       name: Setup Environment
 
     - run: |