TestVariation clean up process does clean up project main branch (#157)

closes Visual-Regression-Tracker/Visual-Regression-Tracker#290

Author: pashidlos

src/shared/tasks/tasks.service.ts

@@ -24,6 +24,7 @@ export class TasksService {
       const testVariations = await this.prismaService.testVariation.findMany({
         where: {
           updatedAt: { lte: dateRemoveAfter },
+          branchName: { not: project.mainBranchName },
         },
       });
       this.logger.debug(