Fix tests

[harrahx3]

Fix some problems with the dependencies version and models edge cases:

• Fix depreciated: 'h' rather than 'H' for time freq
• Force to use pandas 2 and pandapipes 0.12 (upgrading to pandapipes 0.13 doesn't work !)
• Fix edge cases in SHS and HX models
• remove tests network_balance (replaced by energy_system)
• update gitignore

[harrahx3]

Created issue #80 to be solved later

[harrahx3]

@pmohanty943 @EPrade
Can one of you review this PR ?
It should solved the tests hat are not passing in the other PRs