Description:

When switching the registry of an already installed package without changing its version, the Unity Package Manager scripting events {{registeredPackages}} and {{registeringPackages}} are not fired. This causes issues for workflows that rely on these events to detect package updates or changes in dependencies.

Steps to reproduce:

1.  Add the following scope registry to manifest.json:

{code:java}
{
"name": "npmjs",
"url": "https://registry.npmjs.org/",
"scopes": [
"com.stansassets"
]
}
{code}

1.  Add the package {{com.stansassets.scene-management@0.1.1-preview}} in the Unity project.
2.  Modify the scoped registry configuration to use OpenUPM instead

{code:java}
{
"name": "OpenUPM",
"url": "https://package.openupm.com",
"scopes": [
"com.stansassets"
]
}
{code}

1. Wait for the {{resolve}} operation to be completed

Actual results: 
Observe that the {{registeredPackages}} and {{registeringPackages}} events are not triggered after switching the registry.

Expected results: 
The {{registeredPackages}} and {{registeringPackages}} events should trigger when a package's registry changes, even if the package version remains the same.

Note:
The packages are correctly installed from the correct registry, it is just the event that are not triggered.