Merge pull request juju#18548 from ycliuhw/remove-environ-upgrader

juju#18548

This PR removes the IAAS and CAAS environ upgrader workers and the related facades.
We will redesign and implement the environ upgrades later.

## Checklist

- [x] Code style: imports ordered, good names, simple structure, etc
- [x] Comments saying why design decisions were made
- [x] Go unit tests, with comments saying what you're testing
- [ ] ~[Integration tests](https://github.com/juju/juju/tree/main/tests), with comments saying what you're testing~
- [ ] ~[doc.go](https://discourse.charmhub.io/t/readme-in-packages/451) added or updated in changed packages~

## QA steps

```
juju deploy ubuntu

juju destroy-controller k1 --destroy-all-models

```

## Documentation changes

No

## Links

**Jira card:** [JUJU-7232](https://warthogs.atlassian.net/browse/JUJU-7232)



[JUJU-7232]: https://warthogs.atlassian.net/browse/JUJU-7232?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

api/facadeversions.go

@@ -55,7 +55,6 @@ var facadeVersions = facades.FacadeVersions{
 	"Deployer":                     {1},
 	"DiskManager":                  {2},
 	"EntityWatcher":                {2},
-	"EnvironUpgrader":              {1},
 	"ExternalControllerUpdater":    {1},
 	"FilesystemAttachmentsWatcher": {2},
 	"Firewaller":                   {7},

apiserver/allfacades.go

@@ -79,7 +79,6 @@ import (
 	"github.com/juju/juju/apiserver/facades/controller/crosscontroller"
 	"github.com/juju/juju/apiserver/facades/controller/crossmodelrelations"
 	"github.com/juju/juju/apiserver/facades/controller/crossmodelsecrets"
-	"github.com/juju/juju/apiserver/facades/controller/environupgrader"
 	"github.com/juju/juju/apiserver/facades/controller/externalcontrollerupdater"
 	"github.com/juju/juju/apiserver/facades/controller/firewaller"
 	"github.com/juju/juju/apiserver/facades/controller/imagemetadata"
@@ -201,7 +200,6 @@ func AllFacades() *facade.Registry {
 	externalcontrollerupdater.Register(registry)
 	deployer.Register(registry)
 	diskmanager.Register(registry)
-	environupgrader.Register(registry)
 	firewaller.Register(registry)
 	highavailability.Register(registry)
 	hostkeyreporter.Register(registry)