Bump k8s.io/code-generator in /tools in the gomod group

Bumps the gomod group in /tools with 1 update: [k8s.io/code-generator](https://github.com/kubernetes/code-generator).


Updates `k8s.io/code-generator` from 0.31.0 to 0.31.1
- [Commits](kubernetes/code-generator@v0.31.0...v0.31.1)

---
updated-dependencies:
- dependency-name: k8s.io/code-generator
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: gomod
...

Signed-off-by: dependabot[bot] <support@github.com>

tools/go.mod

@@ -4,7 +4,7 @@ go 1.22.0
 
 require (
 	github.com/uw-labs/lichen v0.1.7
-	k8s.io/code-generator v0.31.0
+	k8s.io/code-generator v0.31.1
 )
 
 require (

tools/go.sum

@@ -109,8 +109,8 @@ gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-k8s.io/code-generator v0.31.0 h1:w607nrMi1KeDKB3/F/J4lIoOgAwc+gV9ZKew4XRfMp8=
-k8s.io/code-generator v0.31.0/go.mod h1:84y4w3es8rOJOUUP1rLsIiGlO1JuEaPFXQPA9e/K6U0=
+k8s.io/code-generator v0.31.1 h1:GvkRZEP2g2UnB2QKT2Dgc/kYxIkDxCHENv2Q1itioVs=
+k8s.io/code-generator v0.31.1/go.mod h1:oL2ky46L48osNqqZAeOcWWy0S5BXj50vVdwOtTefqIs=
 k8s.io/gengo/v2 v2.0.0-20240228010128-51d4e06bde70 h1:NGrVE502P0s0/1hudf8zjgwki1X/TByhmAoILTarmzo=
 k8s.io/gengo/v2 v2.0.0-20240228010128-51d4e06bde70/go.mod h1:VH3AT8AaQOqiGjMF9p0/IM1Dj+82ZwjfxUP1IxaHE+8=
 k8s.io/klog/v2 v2.130.1 h1:n9Xl7H1Xvksem4KFG4PYbdQCQxqc/tTUyrgXaOhHSzk=