Deprecated plugins are depending on other plugins so if I want to uninstall deprecated plugin first, I need to uninstall dependency plugins but in this case dependency plugins are not deprecated so my question is how can i delete deprecated plugin when that plugin have dependency.
You seem to have mixed something up because you described the wrong order.
If deprecated plugin A, in this case Multi-Branch Project Plugin, depends on not deprecated plugin B, in this case Environment Script plugin, and you would like to uninstall plugin A, you can go ahead and do that.
Environment Script plugin does not stop you from uninstalling Multi-Branch Project Plugin in any way.
You described the inverse order, which is not how dependency resolution works.
Please take a careful look at my last response, where I describe how dependencies work and how you mix up the underlying issue.
If the option to uninstall a plugin is disabled, you have another plugin installed depending on the Multi-Branch Project Plugin.
The option is not disabled because the Multi-Branch Project Plugin depends on some other plugin.
This is a major difference.
Furthermore, the multibranch plugin does not declare a direct dependency on the environment script plugin: Multi-Branch Project (DEPRECATED), which backs up my former point.
I tried to replicate your case on 2.393 installing both plugins, and I am able to uninstall both plugins independently from each other perfectly fine.