feat: upgrade to hugr v0.27.1

[acl-cqc]

Mostly this was straightforward, with only scope.rs requiring a switch from portgraph algorithms to petgraph.

That is, until command.rs and CommandIterator, which raise many problems with SchedulingGraph. I tried a few other approaches simulating API changes to Hugr but these only worked if Hugr were to expose many more details of the internals of SchedulingGraph than desired. However, Circuit and CommandIterator are planned for removal anyway, so instead I've left CommandIterator using the deprecated region_portgraph with a comment about the various things we can do when region_portgraph is removed (if CommandIterator hasn't been removed first).

[codecov]

Codecov Report

❌ Patch coverage is 95.65217% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 84.04%. Comparing base (4fc5a25) to head (7b1a257).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
tket/src/portmatching/matcher.rs	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1568      +/-   ##
==========================================
+ Coverage   83.70%   84.04%   +0.34%     
==========================================
  Files         188      188              
  Lines       29036    29121      +85     
  Branches    27932    27995      +63     
==========================================
+ Hits        24304    24475     +171     
+ Misses       3569     3473      -96     
- Partials     1163     1173      +10     

Flag	Coverage Δ
python	92.39% <ø> (-0.04%)	⬇️
qis-compiler	91.66% <ø> (ø)
rust	83.71% <95.65%> (+0.35%)	⬆️

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