ci: set TZ for deterministic date tests

Author: ClaudiuCeia

.github/workflows/pages.yml

@@ -17,6 +17,10 @@ concurrency:
 jobs:
   build:
     runs-on: ubuntu-latest
+    env:
+      # Time parsing currently depends on local timezone (Date parsing). The test
+      # suite expects EET/EEST semantics (UTC+2/UTC+3).
+      TZ: Europe/Bucharest
     steps:
       - name: Checkout
         uses: actions/checkout@v4