Update kube crate to version v0.71.0 and policy-evaluator to v0.2.18.

The kube crate version v0.71.0 added support for ECDSA algorithm. Which
is necessary to fix a certificate issue when trying to run PolicyServer
in K3D and Minikube cluster. This commit updates the crate version to
fix the issue.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "policy-server"
-version = "0.2.7"
+version = "0.2.8"
 authors = [
   "Flavio Castelli <fcastelli@suse.com>",
   "Rafael Fernández López <rfernandezlopez@suse.com>",
@@ -12,12 +12,12 @@ edition = "2018"
 anyhow = "1.0"
 async-stream = "0.3.3"
 itertools = "0.10.3"
-policy-evaluator = { git = "https://github.com/kubewarden/policy-evaluator", tag = "v0.2.16" }
+policy-evaluator = { git = "https://github.com/kubewarden/policy-evaluator", tag = "v0.2.18" }
 kubewarden-policy-sdk = "0.3.2"
 lazy_static = "1.4.0"
 clap = { version = "3.0.15", features = [ "cargo", "env" ] }
 futures-util = "0.3.21"
-kube = { version = "0.68.0", default-features = false, features = ["client", "rustls-tls"] }
+kube = { version = "0.71.0", default-features = false, features = ["client", "rustls-tls"] }
 k8s-openapi = { version = "0.14.0", default-features = false, features = ["v1_22"] }
 hyper = { version = "0.14", features = ["full"] }
 num_cpus = "1.13.1"