chore: Forbid local user from inviting remote user to a public room

[jason-famedly]

requires #61
bullet point 2 of famedly/product-management#2925

Public rooms do not require an invite to join, but placing such an invite can circumvent the required blocking. By not allowing such an invite to be created, this should prevent that circumvention

[nico-famedly]

Do we have no tests, that test inviting into a public room after creation? Could you add a short one for that?

[jason-famedly]

um, what happened?

[jason-famedly]

not sure why this closed. I didn't hit that button

[jason-famedly]

open

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.94%. Comparing base (0301c42) to head (409764c).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #59      +/-   ##
==========================================
+ Coverage   97.92%   97.94%   +0.01%     
==========================================
  Files           9        9              
  Lines         772      778       +6     
  Branches      106      109       +3     
==========================================
+ Hits          756      762       +6     
  Misses         16       16              

Files with missing lines	Coverage Δ
synapse_invite_checker/invite_checker.py	96.94% <100.00%> (+0.04%)	⬆️

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[jason-famedly]

Do we have no tests, that test inviting into a public room after creation? Could you add a short one for that?

c0236b3
There were, just got mixed up somewhere. Its a partial unblock of one of the newer ones