Fix build_only for libtorch (#60615)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/60605
We have the `build_only` defined, but the config.yml doesn't have the parameter, this PR fixed that. As a result, the docker image push will be skipped
```
// in config.yml
if [ -z "${BUILD_ONLY}" ]; then
```
```
("11.1", [
("3.8", [
("shard_test", [XImportant(True)]),
("libtorch", [
(True, [
('build_only', [X(True)]),
]),
]),
]),
]),
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60615
Reviewed By: albanD
Differential Revision: D29351567
Pulled By: zhouzhuojie
fbshipit-source-id: dab78bb91f62e8bed47739377987167fea1602cb
