ci: add next to workflow branch filters

Author: kvinwang

.github/workflows/mkosi-build.yml

@@ -25,7 +25,7 @@ on:
   # would be silently dropped. The static job costs seconds and the image build
   # is gated by its own `if`, so an unfiltered push trigger is cheap.
   push:
-    branches: [master]
+    branches: [master, next]
     tags: ['mkosi-os-v*']
 
 concurrency:

.github/workflows/spdx-check.yml

@@ -6,9 +6,9 @@ name: SPDX License Check
 
 on:
   push:
-    branches: [ master, main ]
+    branches: [ master, next ]
   pull_request:
-    branches: [ master, main ]
+    branches: [ master, next ]
 
 jobs:
   reuse-lint: