[REVERT] Rename sdk-v1 to legacy (#5168)

Reverts changes from #5164 and rename dependencies to
`legacy`

Author: frascuchon

argilla/docs/how_to_guides/migrate_from_legacy_datasets.md

@@ -28,7 +28,7 @@ The guide will take you through three steps:
 
 Connect to the Argilla V1 server via the new `argilla` package. First, you should install an extra dependency:
 ```bash
-pip install "argilla[sdk-v1]"
+pip install "argilla[legacy]"
 ```
 
 Now, you can use the `v1` module to connect to the Argilla V1 server.

argilla/pyproject.toml

@@ -22,7 +22,7 @@ io = [
     "datasets>=2.0.0",
 ]
 
-sdk-v1 = [
+legacy = [
     "argilla-v1[listeners]",
 ]
 

argilla/src/argilla/v1/__init__.py

@@ -18,7 +18,7 @@
     from argilla_v1 import *  # noqa
 except ModuleNotFoundError as ex:
     raise Exception(
-        'The package argilla-v1 is not installed. Please install it by typing: pip install "argilla[sdk-v1]"',
+        'The package argilla-v1 is not installed. Please install it by typing: pip install "argilla[legacy]"',
     ) from ex