Validate output of `make generate` in a presubmit to make sure it is run

[vivek-koppuru]

Add a presubmit to validate output of make generate when creating the generated code in the api package. Right now, we just have a suggestion to remind the user to do this manually, but adding a presubmit ensures that code won't get merged unless this target is run.

https://github.com/aws/eks-anywhere/blob/f454a4acff5c1daf7246bd2ac379c5d2c6cfa4a9/pkg/api/v1alpha1/tinkerbelldatacenterconfig_types.go#L11

https://github.com/aws/eks-anywhere/blob/f5a58040f7a35f56806c8840f71cc788d8292d52/Makefile#L363-L364