Chore: update GitHub workflows (#374)

* Trigger assets on `v*.*` branches

* Trigger tests on `v*.*` branches

Author: kraleppa

.github/workflows/assets.yaml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - main
+      - "v*.*"
 
 jobs:
   build:

.github/workflows/elixir-ci.yaml

@@ -7,9 +7,12 @@ name: Elixir CI
 
 on:
   push:
-    branches: ["main"]
+    branches:
+      - main
+      - "v*.*"
   pull_request:
-    branches: ["main"]
+    branches:
+      - main
 
 permissions:
   contents: read