Run ci workflow on branch or PR, not both

.github/workflows/ci.yml

@@ -1,6 +1,8 @@
 name: CI
 on:
   push:
+    branches: 
+      - master
     paths-ignore:
       - '.dockerignore'
       - '.github/workflow/e2e.yml'
@@ -15,6 +17,8 @@ on:
       - 'tests/e2e/**'
   # Hmm, annoying, do we really have to duplicate this?
   pull_request:
+    branches: 
+      - master
     paths-ignore:
       - '.dockerignore'
       - '.github/workflow/e2e.yml'
@@ -43,4 +47,4 @@ jobs:
       with:
         rust-version: ${{ matrix.rust }}
     - run: cargo build --verbose
-    - run: cargo test --verbose
+    - run: cargo test --verbose