ci: remove bazel job from Travis (#22170)

This saves us an executor on Travis.

Note that we still do a bazel build on travis when we run the integration tests under e2e_2.

We expect that CircleCI is the only place we'll ever consume bazel-built artifacts.

PR Close #22170

.travis.yml

@@ -56,7 +56,6 @@ env:
     - CI_MODE=aio
     - CI_MODE=aio_e2e AIO_SHARD=0
     - CI_MODE=aio_e2e AIO_SHARD=1
-    - CI_MODE=bazel
 
 matrix:
   fast_finish: true

scripts/ci/test-bazel.sh

@@ -1,5 +0,0 @@
-#!/usr/bin/env bash
-
-set -u -e -o pipefail
-
-bazel build --config=ci packages/...

scripts/ci/test.sh

@@ -46,7 +46,4 @@ case ${CI_MODE} in
   aio_e2e)
     ${thisDir}/test-aio-e2e.sh
     ;;
-  bazel)
-    ${thisDir}/test-bazel.sh
-    ;;
 esac