add launchpad token action to get tokens

[sliu008]

This pull request introduces a new reusable GitHub Action for retrieving Launchpad tokens via AWS Lambda and integrates it into the umm_t_sync workflow. The workflow now dynamically fetches tokens for both OPS and UAT environments instead of relying on static secrets. The most important changes are:

New GitHub Action for Token Retrieval:

• Added .github/workflows/launchpad-token/action.yml, which defines a composite action to obtain a Launchpad token by invoking an AWS Lambda function. This action configures AWS credentials, calls the Lambda, processes the response, and outputs the token securely.

Integration into Workflow:

• Updated .github/workflows/umm_t_sync.yml to use the new launchpad-token action for both OPS and UAT environments, replacing the use of static secrets with dynamic token retrieval.

Environment Variable Updates:

• Modified the environment variables in the Run cmr_association_diff command step to use the dynamically retrieved tokens from the previous steps, increasing security and flexibility.

Token Usage in Commands:

• Updated the cmr_association_diff command invocations to use the new environment variables for tokens instead of referencing the old secrets directly.