Rollback of commit 6eea9bd27fc88129ccb2d74c1b550e83ebf39f17.

*** Reason for rollback ***

Broke Mac local builds

*** Original change description ***

Add export ZERO_AR_DATE=1 to libtool.sh removing possible timestamp issues.

--
MOS_MIGRATED_REVID=124258787
diff --git a/src/tools/xcode/libtool/libtool.sh b/src/tools/xcode/libtool/libtool.sh
index 00fa9e7..c72f229 100755
--- a/src/tools/xcode/libtool/libtool.sh
+++ b/src/tools/xcode/libtool/libtool.sh
@@ -26,9 +26,6 @@
 MY_LOCATION=${MY_LOCATION:-"$0.runfiles/bazel_tools/tools/objc"}
 WRAPPER="${MY_LOCATION}/xcrunwrapper.sh"
 
-# Ensure 0 timestamping for binary identical results.
-export ZERO_AR_DATE=1
-
 # TODO(b/28347228): When all callers of "xcrunwrapper libtool" are migrated to
 # using this script, move the symlinking behavior to this script.
 "${WRAPPER}" libtool "$@"