Issue with astropy version>=6.0 and gammapy v1.1

[MicaelAndrade]

Gammapy version
v1.1

Bug description
I was trying to make a new gammapy installation and found this problem happening:
No module named 'astropy.coordinates.angle_utilities
When using gammapy code that import astropy's angle_utilities functions.

To Reproduce
I believe just updating astropy to version 6.0.0 would make this error happen.

Other information
I believe this happened because of the new astropy version 6.0.0 from two weeks ago:
"Removed deprecated angle parsing and formatting utilities from angle_utilities. Use the functions from angle_formats instead."
Edit: I temporarily fixed this by reverting to Astropy version 5.3.4. However, when installing Gammapy, the latest version of Astropy (6.0.0) is currently being installed, which may pose a problem for new users.

[github-actions[bot]]

Merci! We will respond to your issue shortly. In the meantime, try import gammapy; gammapy.song()

[registerrier]

Thanks @MicaelAndrade . Indeed, one has to impose astropy<6.0 for gammapy 1.0.1 and 1.1.

The recently released 1.0.2 is compatible with astropy v6.0 and so will be v1.2. For now, we don't plan to release a v1.1.1

[lhaerer]

A similar issue seems to exist with pydantic. I had to impose pydantic==1.4 (current version is 2.5.3).

[registerrier]

This is solved with v1.0.2 and 1.2. With v1.1 be careful to impose astropy<6.0 and pydantic<2.0.

Moving this to discussions, to keep track of the possible installation issue.