Allow adjacent points in sounding to have the same pressure

[sgdecker]

This commit relaxes the monotonicity check that had been performed, as
real data has a tendency to repeat pressures, especially in the stratosphere.

Closes #2077

[dopplershift]

If you can do a git rebase main after syncing things this should pass.

[mvoss-wx]

Hi, A couple newbie questions here.

• For non regular git/python users, will this fix be incorporated in next Metpy1.X release?
• This seems like a general fix for sounding data, will this also fix the more specific case of the same error that generates from the prof = mpcalc.parcel_profile function? (still not sure how a function can create a bad profile)
  thanks

[dopplershift]

This fix will be in the next release, 1.2.

parcel_profile generates a profile for all the pressures given (without needing to check those pressures), so it's "bad" due to the original pressures given (from the data).