chore: ignore sharded functional test artifacts

Author: Zk2u

.gitignore

@@ -64,6 +64,7 @@ target/
 # Tests artifacts
 mutants.out*
 lcov.info
+functional-tests/_dd_parallel_shard*/
 
 # Unit test / coverage reports
 htmlcov/
@@ -97,4 +98,4 @@ fuzz-*.log
 
 # Docker volume data
 docker/vol/fdb/data/
-docker/vol/mosaic-*/tables/
+docker/vol/mosaic-*/tables/