RUBY-3601 Wrap error when mongocrypt_kms_ctx_fail returns false

[comandeo-mongo]

When a KMS request exhausts its retries, mongocrypt_kms_ctx_fail returns
false. Previously the driver re-raised only the last network error, discarding
the status message from mongocrypt_ctx_kms_status that indicates a retry
occurred (e.g. "KMS request failed after 3 retries due to a network error").

This wraps the status message with the last attempt's error so users get
actionable information about both the retry exhaustion and the underlying
cause. Mirrors the approach suggested in MONGOCRYPT-752 and used by the Python
and C drivers.

Changes

• lib/mongo/crypt/binding.rb: add Binding.kms_ctx_status to read the KMS
  context status into a Status without raising; check_kms_ctx_status now
  reuses it.
• lib/mongo/crypt/context.rb: on retry exhaustion, feed_kms raises a
  KmsError combining the status message with the last error, via the new
  raise_kms_retry_error helper.
• spec/integration/client_side_encryption/kms_retry_prose_spec.rb: assert the
  wrapped message includes "last attempt failed with:".

Test plan

• bundle exec rubocop lib/mongo/crypt/binding.rb lib/mongo/crypt/context.rb spec/integration/client_side_encryption/kms_retry_prose_spec.rb — no offenses
• bundle exec rspec spec/integration/client_side_encryption/kms_retry_prose_spec.rb against local cluster + KMS failpoint mock — 3 AWS examples pass (GCP/Azure pending as before)

Jira: https://jira.mongodb.org/browse/RUBY-3601

[Copilot]

Pull request overview

Improves client-side encryption KMS retry error reporting by preserving the libmongocrypt KMS context status message when retries are exhausted, and wrapping it together with the last network failure message to provide more actionable diagnostics.

Changes:

• Added Mongo::Crypt::Binding.kms_ctx_status to retrieve a KMS context Status without raising, and refactored check_kms_ctx_status to use it.
• Updated Mongo::Crypt::Context#feed_kms to raise a wrapped Mongo::Error::KmsError on retry exhaustion via raise_kms_retry_error.
• Tightened the KMS retry prose spec to assert the new wrapped message includes last attempt failed with:.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
lib/mongo/crypt/binding.rb	Exposes KMS ctx status retrieval without raising and reuses it in existing status-check helper.
lib/mongo/crypt/context.rb	Wraps retry-exhaustion status message with the last network error for improved KMS failure diagnostics.
spec/integration/client_side_encryption/kms_retry_prose_spec.rb	Verifies the new wrapped error message format.

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