fixed Spotify's deprecation of http and localhost

[sandrzejewskipl]

• Added warnings and updated docs due to Spotify's deprecation of HTTP and "localhost" redirect URIs

fixes #1186

[stephanebruckert]

Hey, just saw that, thanks for doing the changes!

For the tests to pass I might have to update the redirect URI in the Spotify API app. I will check and let you know

[stephanebruckert]

I added http://127.0.0.1:8080, but doesn't look like it helps
I then removed http://localhost:8080, also tried to re-generate the app credentials, same thing.
Currently both URIs are set

[stephanebruckert]

Oh got it, because you are a first-time contributor you don't have access to GHA secrets https://github.com/spotipy-dev/spotipy/actions/runs/13355321896/job/37440513555#step:5:5
Just adding a comment then we can merge!