don't try to create a version on pull requests

The necessary keys to do so aren't available (and of course we don't try
to post a release on pull requests, anyway).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

.github/workflows/android.yml

@@ -58,6 +58,7 @@ jobs:
 
     - name: create version number
       id: version_number
+      if: github.event_name == 'push'
       run: |
         latest=$(cat ../nightly-builds/latest-subsurface-buildnumber)
         today=$(date '+%Y-%m-%d')

.github/workflows/mac.yml

@@ -56,6 +56,7 @@ jobs:
 
     - name: create version number
       id: version_number
+      if: github.event_name == 'push'
       run: |
         latest=$(cat ../nightly-builds/latest-subsurface-buildnumber)
         today=$(date '+%Y-%m-%d')

.github/workflows/windows.yml

@@ -50,6 +50,7 @@ jobs:
 
     - name: create version number
       id: version_number
+      if: github.event_name == 'push'
       run: |
         latest=$(cat ../nightly-builds/latest-subsurface-buildnumber)
         today=$(date '+%Y-%m-%d')