ci: Allow gpg signed commits to pass DCO checks

[c-warren]

Summary

Allow gpg signed commits to pass DCO checks

DCO has been introduced to verify that each commit in the repository has been signed-off by the developer who is committing it. There are two ways to do this:

• `git commit -s -m "my message"
• sign each commit with a gpg key

This PR allows both of these methods to pass the check, rather than just the first.

Type of Change

• Add new API(s)
• Add new data type(s)
• Add new field(s) to existing data type
• Remove field(s) from data type
• Remove data type(s)
• Remove API(s)
• Other (please provide detailed description)

Data Effect

• Does it change the data stored in database?

Detailed Description

[In-depth description of the changes made to the IDL, specifying new fields, removed fields, or modified data structures]

Impact Analysis

• Backward Compatibility: [Analysis of backward compatibility]
• Forward Compatibility: [Analysis of forward compatibility]

Testing Plan

• Unit Tests: [Do we have unit test covering the change?]
• Persistence Tests: [If the change is related to a data type which is persisted, do we have persistence tests covering the change?]
• Integration Tests: [Do we have integration test covering the change?]
• Compatibility Tests: [Have we done tests to test the backward and forward compatibility?]

Rollout Plan

• What is the rollout plan?
• Does the order of deployment matter?
• Is it safe to rollback? Does the order of rollback matter?
• Is there a kill switch to mitigate the impact immediately?