Delete googlecloudspanner receiver

[atoulme]

Component(s)

receiver/googlecloudspanner

Describe the issue you're reporting

This component is marked unmaintained as of 3 months ago. On 12/4/24, we will open a PR to delete this code unless the codeowners gets back in touch or new codeowners join this module.

[crobert-1]

Related: #32651

@varunraiko: Please respond if you're still able to help maintain this component, otherwise we'll continue with the deletion process as stated.

[codeboten]

The component has been unmaintained for some time and is set to be removed in Oct, see #32651. Closing this as a duplicate issue