Update module github.com/gardener/gardener to v1.131.4 (#206)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

go.mod

@@ -6,7 +6,7 @@ toolchain go1.25.4
 
 require (
 	github.com/ahmetb/gen-crd-api-reference-docs v0.3.0
-	github.com/gardener/gardener v1.131.3
+	github.com/gardener/gardener v1.131.4
 	github.com/go-logr/logr v1.4.3
 	github.com/golang/mock v1.6.0
 	github.com/onsi/ginkgo/v2 v2.27.2

go.sum

@@ -164,8 +164,8 @@ github.com/gardener/cert-management v0.18.0 h1:s2YhkN8z7lXe9En52GCeqQ9be10uEbLtH
 github.com/gardener/cert-management v0.18.0/go.mod h1:9+JT+EBJB2OIX65EG+P1p/DZ/UJ3W8WR0h40ZjKbw+Q=
 github.com/gardener/etcd-druid/api v0.33.0 h1:YwgsYYldaLig2laJMAAMX/dg9/XsQx/LPz8+iL52V6w=
 github.com/gardener/etcd-druid/api v0.33.0/go.mod h1:Qpl1PDJ+bKa6OPWk4o7WBzvjPqZc/CxIXbiTkdRhCrg=
-github.com/gardener/gardener v1.131.3 h1:zd1e7X8fbFUsuhfIqIUyarxWqesxC2Z+NaJbeY7PkBQ=
-github.com/gardener/gardener v1.131.3/go.mod h1:SAUHqtQtT/PDUKClTwbH9/pyEUc2sB1VBl6ko3EC2p4=
+github.com/gardener/gardener v1.131.4 h1:q8Xbp7N1PVMu+VVK/6LpO2+KUEwb2se6SLdhm6qOPM8=
+github.com/gardener/gardener v1.131.4/go.mod h1:SAUHqtQtT/PDUKClTwbH9/pyEUc2sB1VBl6ko3EC2p4=
 github.com/gardener/machine-controller-manager v0.60.2 h1:lY6z67lDlwl9dQUEmlJbrmpxWK10o/rVRUu4JB7xK4U=
 github.com/gardener/machine-controller-manager v0.60.2/go.mod h1:8eE1qLztrWIbOM71mHSQGaC6Q+pl5lvOyN08qP39D7o=
 github.com/ghodss/yaml v0.0.0-20150909031657-73d445a93680/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=