delete unused grpc_master.cfg

tools/internal_ci/linux/grpc_master.cfg

@@ -1,30 +0,0 @@
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# Config file for the internal CI (in protobuf text format)
-
-# Location of the continuous shell script in repository.
-build_file: "grpc/tools/internal_ci/linux/grpc_run_tests_matrix.sh"
-timeout_mins: 240
-action {
-  define_artifacts {
-    regex: "**/*sponge_log.xml"
-    regex: "github/grpc/reports/**"
-  }
-}
-
-env_vars {
-  key: "RUN_TESTS_FLAGS"
-  value: "-f basictests linux --inner_jobs 16 -j 1 --internal_ci --bq_result_table aggregate_results"
-}