OCPBUGS-35752: capi/aws: disable EKS controller in CAPA

The EKS controller feature gate is enabled by default in CAPA, which
causes the following lines to show up in the logs:

```
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613409     349 logger.go:75] \"enabling EKS controllers and webhooks\" logger=\"setup\""
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613416     349 logger.go:81] \"EKS IAM role creation\" logger=\"setup\" enabled=false"
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613420     349 logger.go:81] \"EKS IAM additional roles\" logger=\"setup\" enabled=false"
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613425     349 logger.go:81] \"enabling EKS control plane controller\" logger=\"setup\""
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613449     349 logger.go:81] \"enabling EKS bootstrap controller\" logger=\"setup\""
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613464     349 logger.go:81] \"enabling EKS managed cluster controller\" logger=\"setup\""
time="2024-06-18T11:43:59Z" level=debug msg="I0618 11:43:59.613496     349 logger.go:81] \"enabling EKS managed machine pool controller\" logger=\"setup\""
```

Although harmless, they can be confusing for users. This change
disables the feature so the lines are gone and we are not running
controllers unnecessarily.

Author: r4f4

pkg/clusterapi/system.go

@@ -150,7 +150,7 @@ func (c *system) Run(ctx context.Context) error {
 				"--health-addr={{suggestHealthHostPort}}",
 				"--webhook-port={{.WebhookPort}}",
 				"--webhook-cert-dir={{.WebhookCertDir}}",
-				"--feature-gates=BootstrapFormatIgnition=true,ExternalResourceGC=true,TagUnmanagedNetworkResources=false",
+				"--feature-gates=BootstrapFormatIgnition=true,ExternalResourceGC=true,TagUnmanagedNetworkResources=false,EKS=false",
 			},
 			map[string]string{},
 		)