Stabilize module configgrpc

[mx-psi]

Before stabilizing a module, an approver or maintainer must make sure that the following criteria have been met for at least two successive minor version releases (regardless of when this issue was opened):

• No open issues or PRs in the module that would require breaking changes
• No TODOs in the module code that would require breaking changes
• No deprecated symbols in the module
• No symbols marked as experimental in the module
• The module follows the Coding guidelines

Please also make sure to publicly announce our intent to stabilize the module on:

• The #otel-collector CNCF Slack Channel
• The #opentelemetry CNCF Slack channel
• A Collector SIG meeting (if unable to attend, just add to the agenda)

To help other people verify the above criteria, please link to the announcement and other links used to complete the above in a comment on this issue.

Once all criteria are met, close this issue by moving this module to the stable module set.

[atoulme]

Announced at SIG meeting 3/13.

[jpkrohling]

I can take this one if nobody is working on it.

[jpkrohling]

Related: #7646

[atoulme]

https://cloud-native.slack.com/archives/C01N6P7KR6W/p1721546467635659 and https://cloud-native.slack.com/archives/CJFCJHG4Q/p1721546482895639

[jpkrohling]

No open issues or PRs in the module that would require breaking changes

I'm currently working on this.

[atoulme]

This issue #9480 needs to be resolved.

[jpkrohling]

This as well: #9478

[jpkrohling]

I just finished going through all the open issues and PRs related to gRPC, and I believe only the two issues from the previous comments would be required for v1. All others can be addressed post-v1.