Disable nightly builds

They don't properly work since the conan2 migration, and it seems nobody is actually using them anymore, so deactivating them for now, and will reactivate when we have fixed the conan packages versions issues.

.github/workflows/nightly-stable.yml

@@ -1,10 +1,10 @@
 name: Nightly build - stable release
 run-name: Nightly build - stable release
 
-on:
-  schedule:
-    # Daily at 5:15 CET
-    - cron: '15 4 * * *'
+# on:
+#   schedule:
+#     # Daily at 5:15 CET
+#     - cron: '15 4 * * *'
 
 jobs:
   build-nightly:

.github/workflows/nightly-testing.yml

@@ -1,10 +1,10 @@
 name: Nightly build - dev release
 run-name: Nightly build - dev release
 
-on:
-  schedule:
-    # Daily at 4:15 CET
-    - cron: '15 3 * * *'
+# on:
+#   schedule:
+#     # Daily at 4:15 CET
+#     - cron: '15 3 * * *'
 
 jobs:
   build-nightly: