respec workflow only on demand

Author: ralfhandl

.github/workflows/respec.yaml

@@ -8,11 +8,8 @@ name: respec
 # on the gh-pages branch when the corresponding markdown files change.
 #
 
-# run this on push to main
+# run this manually from main
 on:
-  push:
-    branches:
-      - main
   workflow_dispatch: {}
 
 jobs:

CONTRIBUTING.md

@@ -218,7 +218,7 @@ The steps for creating a `vX.Y.Z-rel` branch are:
 5. Merge `vX.Y.Z-rel` into `main` via PR
    - this PR should only add files `versions/X.Y.Z.md` and `versions/X.Y.Z-editors.md`
 
-The HTML renderings of the specification versions are automatically generated from the `versions` directory on `main` by the [`respec` workflow](https://github.com/OAI/OpenAPI-Specification/blob/main/.github/workflows/respec.yaml), which generates a pull request for publishing the HTML renderings to the [spec site](https://spec.openapis.org).
+The HTML renderings of the specification versions are generated from the `versions` directory on `main` by manually triggering the [`respec` workflow](https://github.com/OAI/OpenAPI-Specification/blob/main/.github/workflows/respec.yaml), which generates a pull request for publishing the HTML renderings to the [spec site](https://spec.openapis.org).
 
 ### Schema Iterations