feat(crd): Mark certManager as non-experimental

[Techassi]

Closes #626.

Note

A bug fix was needed for this: stackabletech/operator-rs#1109

This PR marks the cert-manager backend es non-experimental by renaming the CRD field from experimentalCertManager to certManager.

[Techassi]

Release Note

==== Platform improvements

===== Stackable secret-operator

*Breaking:* The `certManager` backend is no longer experimental.
In version `v1alpha2` of the SecretClass, the `experimentalCertManager` field was renamed to `certManager`.
See the xref:secret-operator:secretclass.adoc[SecretClass reference] for more details.

[sbernauer]

Ah you beat me by literally a minute :D

[Techassi]

Ah you beat me by literally a minute :D

There is always the option to have more than one reviewer :)

[sbernauer]

I let @adwk67 review, just two leftovers I noticed:

diff --git a/docs/modules/secret-operator/pages/cert-manager.adoc b/docs/modules/secret-operator/pages/cert-manager.adoc
index aa88c1c..50774d2 100644
--- a/docs/modules/secret-operator/pages/cert-manager.adoc
+++ b/docs/modules/secret-operator/pages/cert-manager.adoc
@@ -43,7 +43,7 @@ include::example$cert-manager/issuer.yaml[]
 == Creating a SecretClass
 
 The Stackable Secret Operator needs to know how to request the certificates from Cert-Manager.
-Do this by creating a xref:secretclass.adoc[] using the xref:secretclass.adoc#backend-certmanager[`experimentalCertManager` backend].
+Do this by creating a xref:secretclass.adoc[] using the xref:secretclass.adoc#backend-certmanager[`certManager` backend].
 
 [source,yaml]
 ----
diff --git a/rust/operator-binary/src/crd/secret_class/mod.rs b/rust/operator-binary/src/crd/secret_class/mod.rs
index 068451e..89ce09d 100644
--- a/rust/operator-binary/src/crd/secret_class/mod.rs
+++ b/rust/operator-binary/src/crd/secret_class/mod.rs
@@ -53,8 +53,8 @@ pub mod versioned {
         /// A new certificate and key pair will be generated and signed for each Pod, keys or certificates are never reused.
         AutoTls(AutoTlsBackend),
 
-        /// The [`experimentalCertManager` backend][1] injects a TLS certificate issued
-        /// by [cert-manager](https://cert-manager.io/).
+        /// The [`certManager` backend][1] injects a TLS certificate issued by
+        /// [cert-manager](https://cert-manager.io/).
         ///
         /// A new certificate will be requested the first time it is used by a Pod, it
         /// will be reused after that (subject to cert-manager renewal rules).

[Techassi]

I let @adwk67 review, just two leftovers I noticed:

Ah, nice spotting! I will adjust it asap. Adjusted in 08eaa31.

[sbernauer]

Just for the record @adwk67: We intentional left tests and stuff on v1alpha1 to actually test the conversions

[adwk67]

Tested on Openshift - LGTM!