Point to the CNCF logos

[gbartolini]

We should remove the logos here and point to the official CNCF ones.

[sxd]

Hi @gbartolini

What's the reason for this? Is this mandatory? I'm worry that we're referring the logos somewhere else here and we're changing just here, probably this will require to review everywhere else where we reference the logo, like documentation and other projects?

Regards,

[sxd]

We need to change other places before here:

• https://github.com/cloudnative-pg/charts/blob/main/charts/cloudnative-pg/Chart.yaml#L22
• https://github.com/cloudnative-pg/charts/blob/main/charts/cluster/Chart.yaml#L22

Also I think we should check if those images are referenced on sites like https://artifacthub.io/ or https://operatorhub.io/ before removing anything here