Enable xla build caching (#82342)

### Description
<!-- What did you change and why was it needed? -->
Enable cloud caching for xla build.

### Issue
<!-- Link to Issue ticket or RFP -->
Addresses #78182

### Testing
<!-- How did you test your change? -->
The change/caching was tested in the downstream [workflow](https://app.circleci.com/pipelines/github/pytorch/xla/12306/workflows/ca613a3c-de81-40ad-8498-72ebc65d42f6/jobs/27211)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/82342
Approved by: https://github.com/clee2000
diff --git a/.github/ci_commit_pins/xla.txt b/.github/ci_commit_pins/xla.txt
index 976e4ca..5e23c4e 100644
--- a/.github/ci_commit_pins/xla.txt
+++ b/.github/ci_commit_pins/xla.txt
@@ -1 +1 @@
-33cf8bf71ce1eb946d3736bfe46f112a9231bc4e
+15f12393df9ca4d46ea71a2eeda857942790faee
diff --git a/.jenkins/pytorch/test.sh b/.jenkins/pytorch/test.sh
index 8ad0c31..b476d25 100755
--- a/.jenkins/pytorch/test.sh
+++ b/.jenkins/pytorch/test.sh
@@ -450,7 +450,7 @@
   source "$(dirname "${BASH_SOURCE[0]}")/common-build.sh"
 
   XLA_DIR=xla
-  USE_CACHE=0
+  USE_CACHE=1
   clone_pytorch_xla
   # shellcheck disable=SC1091
   source "xla/.circleci/common.sh"