Drop starsessions from App's requirements (#18470)

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jirka Borovec <[email protected]>
Co-authored-by: Jirka <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

requirements/app/app.txt

@@ -2,7 +2,6 @@ lightning-cloud == 0.5.57  # Must be pinned to ensure compatibility
 packaging
 typing-extensions >=4.4.0, <4.8.0
 deepdiff >=5.7.0, <6.6.0
-starsessions >=1.2.1, <2.0 # strict
 fsspec[http] >=2022.5.0, <2023.11.0
 croniter >=1.3.0, <1.5.0  # strict; TODO: for now until we find something more robust.
 traitlets >=5.3.0, <5.10.0

src/lightning/app/core/api.py

@@ -58,15 +58,6 @@
 from lightning.app.utilities.cloud import is_running_in_cloud
 from lightning.app.utilities.component import _context
 from lightning.app.utilities.enum import ComponentContext, OpenAPITags
-from lightning.app.utilities.imports import _is_starsessions_available
-
-if _is_starsessions_available():
-    from starsessions import SessionMiddleware
-else:
-
-    class SessionMiddleware:  # type: ignore[no-redef]
-        pass
-
 
 # TODO: fixed uuid for now, it will come from the FastAPI session
 TEST_SESSION_UUID = "1234"
@@ -175,9 +166,6 @@ class StateUpdate(BaseModel):
     allow_headers=["*"],
 )
 
-if _is_starsessions_available():
-    fastapi_service.add_middleware(SessionMiddleware, secret_key="secret", autoload=True)  # noqa: S106
-
 
 # General sequence is:
 # * an update is generated in the UI

src/lightning/app/utilities/imports.py

@@ -103,10 +103,6 @@ def _is_streamlit_tensorboard_available() -> bool:
     return module_available("streamlit_tensorboard")
 
 
-def _is_starsessions_available() -> bool:
-    return module_available("starsessions")
-
-
 def _is_gradio_available() -> bool:
     return module_available("gradio")