[CI] Use Xcode 14.2 (#1820)

Looks like CI ~is~ was broken because the [CI fleet was upgraded to
Xcode
14.2](bazelbuild/continuous-integration#1431 (comment))
and some machines were missing the watchOS and tvOS SDKs. Now that the
iMacs are properly set up, we should be able to simply use Xcode 14.2.

We can't use Xcode 13.0 anymore because it doesn't run on macOS Ventura
(which all the x86_64 machines are on after the upgrade).

Future tasks might include adding support for arm64 in our tooling so
that we can switch to run on Mac Studios instead of iMacs.

.bazelci/presubmit.yml

@@ -4,6 +4,7 @@ x_defaults:
   # it doesn't know about; so that is used to avoid repeating common subparts.
   common: &common
     platform: macos
+    xcode_version: "14.2"
     build_targets:
     - "tools/..."
     - "test/..."