LatestReleaseDate and DateAdded should not be allowed in plugin file validation

[jjw24]

LatestReleaseDate and DateAdded are currently set as optional fields and passes validation, this should be not be allowed. @Jack251970 since you improved the plugin file validation area, would you know why these two fields are set as optional?

[Jack251970]

This because these two fields will be added automatically with Github Action. And we need to ensure the combability

[jjw24]

The validation should only happen on the new submitted plugin and we don't validate fields after the merge, so we don't need to worry about compatibility?