fix(ci): increase test timeout to 25 minutes

Tests were timing out after 15 minutes when running in parallel mode.
Most of the time is spent building dependencies (swift-syntax, postgres-nio, etc.)
on first run or cache miss.

Changes:
- Increase timeout from 15m to 25m
- Keep --parallel flag (SnapshotTests already have .serialized trait)

Note: Build time will improve once cache is established and Package.swift stabilizes.

Author: coenttb

.github/workflows/ci.yml

@@ -47,7 +47,7 @@ jobs:
 
       - name: Build and test
         run: swift test --parallel
-        timeout-minutes: 15
+        timeout-minutes: 25
 
   linux:
     name: Linux (Swift ${{ matrix.swift }})
@@ -78,7 +78,7 @@ jobs:
 
       - name: Build and test
         run: swift test --parallel
-        timeout-minutes: 15
+        timeout-minutes: 25
 
   documentation:
     name: Documentation