fix: increase Build & Test timeout from 20 to 35 minutes (#1267)

The hardening PR (#1262) set timeout-minutes: 20, but the un-sharded
`make test` step on develop pushes consistently takes ~25 minutes.
This caused every develop push since the hardening to be cancelled.

Co-authored-by: Ben Coombs <bjcoombs@users.noreply.github.com>

Author: bjcoombs

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
   build:
     name: Build Docker Image
     runs-on: ubuntu-latest
-    timeout-minutes: 20
+    timeout-minutes: 35
 
     steps:
       - name: Checkout code