feature: add EOL settings to gitattributes

Author: DanielMicrosoft

.gitattributes

@@ -15,3 +15,7 @@
 build_scripts/windows/scripts/az eol=lf
 # sh scripts should be LF
 *.sh eol=lf
+
+# Generated latest index assets should always use LF to avoid cross-platform churn
+src/azure-cli-core/azure/cli/core/commandIndex.latest.json text eol=lf
+src/azure-cli-core/azure/cli/core/helpIndex.latest.json text eol=lf