Add S3 GetBucketPolicyStatus support

[OmniNomadLLC]

What

Implements GetBucketPolicyStatus for S3.

Why

Currently the call falls through to a generic empty response: get_bucket_policy_status returns PolicyStatus: {} regardless of whether the bucket has a policy, and never raises NoSuchBucketPolicy. We ran into this while testing a security-audit tool against moto (a tool that checks whether buckets are public), where the empty response is indistinguishable from a private bucket.

How

• NoSuchBucketPolicy when the bucket has no policy (matches AWS).
• IsPublic is computed from the stored policy: an Allow statement with a wildcard principal ("*", {"AWS": "*"} or a list containing "*") and no Condition block makes the policy public. Statements carrying any Condition are treated as non-public, which matches how AWS treats access-restricting condition keys; the full AWS evaluation of which condition keys still count as public is intentionally out of scope and documented as such in the helper.
• Dispatch and ACTION_MAP entries follow the existing GetBucketPolicy/GetPublicAccessBlock patterns; the response uses the ActionResult serializer.

Tests

Four new tests in tests/test_s3/test_s3_bucket_policy.py: no policy raises NoSuchBucketPolicy; wildcard-principal policy reports IsPublic: True; scoped principal reports False; wildcard with a Condition reports False. Full -k "policy or public_access" subset passes (25 tests), ruff check and ruff format clean.

[codecov]

Codecov Report

❌ Patch coverage is 81.25000% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.31%. Comparing base (716d6a8) to head (6209f2a).

Files with missing lines	Patch %	Lines
moto/s3/utils.py	75.00%	6 Missing ⚠️

❌ Your patch check has failed because the patch coverage (81.25%) is below the target coverage (90.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #10214      +/-   ##
==========================================
- Coverage   93.32%   93.31%   -0.01%     
==========================================
  Files        1342     1342              
  Lines      122702   122734      +32     
==========================================
+ Hits       114507   114534      +27     
- Misses       8195     8200       +5     

Flag	Coverage Δ
servertests	27.93% <12.50%> (-0.01%)	⬇️
unittests	93.29% <81.25%> (-0.01%)	⬇️

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