ci: run the derived-variables cypress spec

The cypress step takes an explicit spec list, so a new spec has to be
added to it to run.

.gitea/workflows/build.yaml

@@ -198,7 +198,7 @@ jobs:
           # Start frontend and run cypress
           # timeout 1800: SIGTERM after 30 min so Cypress can flush video/screenshots
           # before the outer timeout-minutes hard-kills the step (avoids silent multi-hour hangs)
-          npx ng serve --host 0.0.0.0 --port 4200 & npx wait-on http://localhost:4200 && timeout 1800 npx cypress run --browser chrome --spec "cypress/e2e/csv-limited.cy.ts,cypress/e2e/hook-programs.cy.ts,cypress/e2e/liveness.cy.ts,cypress/e2e/editor.cy.ts,cypress/e2e/excel-multi-load.cy.ts,cypress/e2e/excel.cy.ts,cypress/e2e/csv.cy.ts,cypress/e2e/filtering.cy.ts,cypress/e2e/filter-panel.cy.ts,cypress/e2e/licensing.cy.ts,cypress/e2e/viewer-labels.cy.ts,cypress/e2e/full-table-search.cy.ts,cypress/e2e/viewbox.cy.ts,cypress/e2e/stage.cy.ts,cypress/e2e/browser-info.cy.ts,cypress/e2e/ddl-export.cy.ts,cypress/e2e/row-cell-limits.cy.ts"
+          npx ng serve --host 0.0.0.0 --port 4200 & npx wait-on http://localhost:4200 && timeout 1800 npx cypress run --browser chrome --spec "cypress/e2e/derived-variables.cy.ts,cypress/e2e/csv-limited.cy.ts,cypress/e2e/hook-programs.cy.ts,cypress/e2e/liveness.cy.ts,cypress/e2e/editor.cy.ts,cypress/e2e/excel-multi-load.cy.ts,cypress/e2e/excel.cy.ts,cypress/e2e/csv.cy.ts,cypress/e2e/filtering.cy.ts,cypress/e2e/filter-panel.cy.ts,cypress/e2e/licensing.cy.ts,cypress/e2e/viewer-labels.cy.ts,cypress/e2e/full-table-search.cy.ts,cypress/e2e/viewbox.cy.ts,cypress/e2e/stage.cy.ts,cypress/e2e/browser-info.cy.ts,cypress/e2e/ddl-export.cy.ts,cypress/e2e/row-cell-limits.cy.ts"
 
       - name: Zip Cypress videos
         if: always()