Remove the feather from the logo

### Use case

See https://news.apache.org/foundation/entry/evolving-the-asf-brand

The ASF would replace the feather with something else, so it is likely we should remove the feather as well.

### Possible solution

We could wait for a new ASF logo and then decide if we adopt it, or we could come up with a completely different one.

### Possible workarounds

_No response_

### JMeter Version

5.5

### Java Version

_No response_

### OS Version

_No response_