fix(warnings): trigger reset warnings at a better stack level

[mcous]

#164 upgraded ruff to include more flake8 bugbear errors, which highlighted that the stacklevel argument to warnings.warn is not used by the warning checker. This results in warnings being attached to an unhelpful decoy-internal call-site.

This PR uses the stacklevel argument of warnings.warn to trigger the warnings at whatever level called decoy.reset. For pytest usage, this results in something like the following:

# before
/Users/mc/projects/decoy/decoy/warning_checker.py:60: MiscalledStubWarning: Stub was called but no matching rehearsal found.
Found 1 rehearsal:
1.	stub(1, 2, 3)
Found 1 call:
1.	stub(4, 5, 6)
  warn(MiscalledStubWarning(calls=unmatched, rehearsals=past_stubs))

# after
/Users/mc/projects/decoy/decoy/pytest_plugin.py:32: MiscalledStubWarning: Stub was called but no matching rehearsal found.
Found 1 rehearsal:
1.	stub(1, 2, 3)
Found 1 call:
1.	stub(4, 5, 6)
  decoy.reset()

[codecov]

Codecov Report

Merging #165 (f921401) into main (97fb55b) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #165   +/-   ##
=======================================
  Coverage   98.36%   98.36%           
=======================================
  Files          19       19           
  Lines         734      736    +2     
  Branches       87       87           
=======================================
+ Hits          722      724    +2     
  Misses         10       10           
  Partials        2        2           

Impacted Files	Coverage Δ
decoy/errors.py	100.00% <ø> (ø)
decoy/matchers.py	89.09% <ø> (ø)
decoy/core.py	100.00% <100.00%> (ø)
decoy/warning_checker.py	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.