Fix the workflow definitions

A while back I changed the name of the
default branch to main, which effectively
disabled the tests and builds.

And so, a test failure creeped in. Now we
have a bug to to fix.

.github/workflows/integration.yml

@@ -1,14 +1,14 @@
 name: Integration
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
-
+    branches: [ main ]
+  schedule:
+    - cron: "43 18 * * 0"
 jobs:
   test:
-    # Pin the version of the docker container used for building.
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - name: Setup bazel
         uses: abhinavsingh/setup-bazel@v3

.github/workflows/test.yml

@@ -1,13 +1,14 @@
 name: Test
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
-
+    branches: [ main ]
+  schedule:
+    - cron: "43 19 * * 0"
 jobs:
   test:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - name: Setup bazel
         uses: abhinavsingh/setup-bazel@v3