chore(deps): update kube requirement from 3.0 to 4.2

[dependabot]

Updates the requirements on kube to permit the latest version.

Release notes

Sourced from kube's releases.

4.2.0

What's Changed

Maintenance release for 4.0.0. Fixes, and https proxy. MSRV 1.89. All PRs here.

Added

• add support for https proxy by @​goenning in kube-rs/kube#2013

Fixed

• Update kube-cel requirement from 0.7.0 to 0.8.0 by @​dependabot[bot] in kube-rs/kube#2017
• client: include sources in CommitError's error message by @​iniw in kube-rs/kube#2020
• Include error sources in Display messages at client, core, runtime by @​doxxx93 in kube-rs/kube#2021
• Remove extraneous Sync bound in Controller::reconcile_all_on by @​bojidar-bg in kube-rs/kube#2029
• client: fall back to OS-native cert store via rustls-platform-verifier by @​aviramha in kube-rs/kube#2030
• Avoid deep-cloning ObjectMeta per event in trigger_owners by @​doxxx93 in kube-rs/kube#2039
• config: resolve relative exec plugin command paths by @​deepu105 in kube-rs/kube#2037
• Construct typed CustomResourceDefinition in derived crd() by @​doxxx93 in kube-rs/kube#2042

New Contributors

• @​iniw made their first contribution in kube-rs/kube#2020
• @​bojidar-bg made their first contribution in kube-rs/kube#2029
• @​deepu105 made their first contribution in kube-rs/kube#2037

Full Changelog: kube-rs/kube@4.0.0...4.2.0

Changelog

Sourced from kube's changelog.

4.2.0 / 2026-07-22

• see kube-rs/kube@4.0.0...main

4.0.0 / 2026-06-16

New Major

As per the release schedule to match up with the latest Kubernetes ハル release. Lots of fixes and improvements. Thanks to everyone who contributed!

Kubernetes v1_36 support via k8s-openapi 0.28

Please upgrade k8s-openapi along with kube to avoid conflicts.

CEL Validation

A new optional crate kube-cel is being re-exported through kube::core::cel via kube-rs/kube#1954

Kubernetes CRDs support CEL validation rules via x-kubernetes-validations, and were supported from 3.0 via KubeSchema, but these rules could only be evaluated server-side by the API server.

The new crate allows evaluating these rules locally using rules matching the upstream Kubernetes CEL libraries.

While low-level, a higher-level CEL validator integrates with CustomResource via #[kube(cel)] from kube-rs/kube#2011 and can be used as;

#[derive(CustomResource, Serialize, Deserialize, Clone, KubeSchema)]
#[kube(group = "example.com", version = "v1", kind = "Foo", namespaced)]
#[kube(cel, validation = "self.spec.replicas >= 0")] // cel trigger + validation rule
struct FooSpec { replicas: i32 }
let foo = Foo::new("test", FooSpec { replicas: -1 });
foo.validate_cel()?;                     // new impl; checks creation rules
new_foo.validate_cel_update(&old_foo)?;  // new impl; checks transition rules

See examples/crd_derive_cel.rs for more details.

This is available under the kube/cel feature, courtesy of @​doxxx93.

Config

A lot of improvements to config handling;

• better error handling of malformed client certs in kube-rs/kube#1966
• add missing Kubeconfig fields in kube-rs/kube#1965
• Kubeconfig future key compatibility for new fields by adding catch-all other key via kube-rs/kube#1964
• deserialization changed from serde-yaml to serde-saphyr to get rid of the long-deprecated dependency. kube-rs/kube#1975

Retry and Timeouts

Better timeout and retry handling to better deal with flaky network conditions, and busy or initializing apiservers.

... (truncated)

Commits

• 526f1f2 release 4.2.0
• 3b811b5 break circular dependency on explicit dev-dep versions
• 48d1ad5 Construct typed CustomResourceDefinition in derived crd() (#2042)
• d0328f7 config: resolve relative exec plugin command paths (#2037)
• 76fee02 ignore multiple versions of syn (#2046)
• fe44fa2 Amortize PredicateFilter cache eviction across polls (#2040)
• 5afcf19 Avoid deep-cloning ObjectMeta per event in trigger_owners (#2039)
• 660966e Chore(deps): Update serde-saphyr requirement from 0.0.27 to 0.0.29 (#2032)
• 0bcb4c7 bump msrv to 1.89 (#2035)
• f671d57 fix deny failures (#2034)
• Additional commits viewable in compare view

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