github actions: run test jobs on pull requests

Passing just `pull_request` as a trigger should run for
any target branch, but the indent was incorrect, hiding
the trigger from the test runner. Go back to running
on push for both supported branches, and for all pull
requests.

.github/workflows/audit.yaml

@@ -1,17 +1,17 @@
 name: Security audit
+
 on:
   push:
     paths:
       - '**/Cargo.toml'
       - '**/Cargo.lock'
   pull_request:
-    branches:
-      main
     paths:
       - '**/Cargo.toml'
       - '**/Cargo.lock'
   schedule:
     - cron: '21 20 2 * *'
+
 jobs:
   audit:
     runs-on: ubuntu-latest

.github/workflows/lint.yaml

@@ -1,13 +1,14 @@
 name: Lint
+
 on:
   push:
     branches:
       - main
+      - speedreader
   pull_request:
-    branches:
-      main
   schedule:
     - cron: '28 20 2 * *'
+
 jobs:
   lint:
     runs-on: ubuntu-latest

.github/workflows/tests.yaml

@@ -5,7 +5,7 @@ on:
     branches:
       - main
       - speedreader
-    pull_request:
+  pull_request:
 
 jobs:
   test: