Avoid canceling jobs after merge (#34)

Better concurrency

.github/workflows/tox.yml

@@ -2,9 +2,6 @@
 name: tox
 
 on:
-  create: # is used for publishing to PyPI and TestPyPI
-    tags: # any tag regardless of its name, no branches
-      - "**"
   push: # only publishes pushes to the main branch to TestPyPI
     branches: # any integration branch but not tag
       - "main"
@@ -13,7 +10,9 @@ on:
       - "main"
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  # Avoids canceling push to main of the same commit (github.sha) but will
+  # cancel running builds when you update the source branch of a PR.
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.ref_name }}-${{ github.event.number || github.sha }}
   cancel-in-progress: true
 
 env: