Add macos-latest to workflow actions

This is a test commit to verify whether existing workflow actions can
run on macos-latest.

See opensearch-project/opensearch-build#38
for more details.

Signed-off-by: Michael Froh <froh@amazon.com>

.github/workflows/backwards_compatibility_tests_workflow.yml

@@ -14,7 +14,7 @@ jobs:
  strategy:
  matrix:
  java: [ 11, 17 ]
- os: [windows-latest, ubuntu-latest]
+ os: [ubuntu-latest, windows-latest, macos-latest]
  bwc_version : [ "2.0.1", "2.1.0", "2.2.1", "2.3.0", "2.4.1", "2.5.0-SNAPSHOT", "2.6.0-SNAPSHOT" ]
  opensearch_version : [ "3.0.0-SNAPSHOT" ]
  exclude:
@@ -87,7 +87,7 @@ jobs:
  strategy:
  matrix:
  java: [ 11, 17 ]
- os: [windows-latest, ubuntu-latest]
+ os: [ubuntu-latest, windows-latest, macos-latest]
  bwc_version: [ "2.6.0-SNAPSHOT" ]
  opensearch_version: [ "3.0.0-SNAPSHOT" ]