Fix rust-server client feature deps for pattern validation

[scarab-systems]

Fixes #23920.

What changed

• Adds lazy_static and regex to the generated rust-server client feature whenever generated models can emit pattern validation statics.
• Keeps callback-only dependencies under the callback branch.
• Adds a focused regression spec/test for pattern validation in generated shared models.
• Regenerates the affected current rust-server sample Cargo manifests.

Why

rust-server shared models can emit lazy_static::lazy_static! and regex::Regex for schema pattern validation even when consumers build only the client feature. Previously, those dependencies were only added to the client feature through the callbacks path, so client-only builds could miss them.

Validation

Targeted validation:

• ./mvnw -pl modules/openapi-generator -am -Dtest=RustServerCodegenTest -Dsurefire.failIfNoSpecifiedTests=false test
• ./mvnw -pl modules/openapi-generator-cli -am package -DskipTests=true -Dmaven.javadoc.skip=true -Djacoco.skip=true
• ./bin/generate-samples.sh ./bin/configs/rust-server-multipart-v3.yaml ./bin/configs/rust-server-no-example-v3.yaml ./bin/configs/rust-server-openapi-v3.yaml ./bin/configs/rust-server-ops-v3.yaml ./bin/configs/rust-server-petstore-with-fake-endpoints-models-for-testing.yaml ./bin/configs/rust-server-ping-bearer-auth-v3.yaml ./bin/configs/rust-server-test.yaml
• (cd samples/server/petstore/rust-server/output/no-example-v3 && cargo check --no-default-features --features client)

Full PR-template sequence:

• ./mvnw clean package
• ./bin/generate-samples.sh ./bin/configs/*.yaml
• ./bin/utils/export_docs_generators.sh

The full sample/doc regeneration completed without additional tracked changes beyond the committed rust-server updates.

Reviewer note

Rust/rust-server reviewers: @frol @farcaller @richardwhiuk @paladinzh @jacob-pro @dsteeley @Metaswitch

PR checklist

• Read the contribution guidelines.
• Run the following full repo-wide build/sample/doc export sequence:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

• Mentioned Rust/rust-server reviewers for the language-specific change.

---

Summary by cubic

Ensures rust-server client-only builds include pattern validation deps by adding lazy_static and regex to the client feature when shared models emit pattern checks. Prevents missing-dependency build failures in projects without callbacks. Fixes #23920.

• Bug Fixes
  • Include lazy_static and regex in the generated client feature when models use pattern validation; keep callback-only deps under the callback branch.
  • Add a focused regression test to assert the client feature includes these deps when pattern statics are emitted.
  • Regenerate affected sample Cargo.toml files.

^{Written for commit 344276e. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 8 files

_{Re-trigger cubic}

[cubic-dev-ai]

No issues found across 8 files

_{Re-trigger cubic}