fix(metro-config): disable unstable_preserveClasses again

[tido64]

Description

✘ [ERROR] Transforming class syntax to the configured target environment ("hermes0.14" + 6 overrides) is not supported yet

    ../../node_modules/.store/react-native-virtual-ff9cec5d8c/package/Libraries/Utilities/createPerformanceLogger.js:5:0:
      5 │ class PerformanceLogger {
        ╵ ~~~~~

✘ [ERROR] Transforming class syntax to the configured target environment ("hermes0.14" + 6 overrides) is not supported yet

    ../../node_modules/.store/react-native-virtual-ff9cec5d8c/package/Libraries/Alert/Alert.js:5:0:
      5 │ class Alert {
        ╵ ~~~~~

Resolves #3951

Test plan

n/a