Make postprocess_on: True the default in the workflow

[singhd789]

Describe your changes

Issue ticket number and link (if applicable)

NOAA-GFDL/fre-cli#847

Checklist before requesting a review

• I ran my code
• I tried to make my code readable
• I tried to comment my code
• I wrote a new test, if applicable
• I wrote new instructions/documentation, if applicable
• I ran pytest and inspected it's output
• I ran pylint and attempted to implement some of it's feedback
• No print statements; all user-facing info uses logging module

Manual Pipeline Run Details

Was the manual pipeline (test_cloud_runner) triggered for this PR?

• Yes
• No

Result of manual pipeline run:

(Paste relevant logs, output, or a link to the workflow run here)

How to trigger the manual pipeline:

The test_cloud_runner pipeline is not automatically associated as a required check with the PR; it must be triggered to test changes in a full post-processing run.

To trigger the manual pipeline:

1. Follow the link to the test_cloud_runner actions tab here

   • you should see "This workflow has a workflow_dispatch event trigger"

2. Click the dropdown "Run workflow":

   a. If trying to merge from a branch on fre-workflows: choose branch from the first drop down, leave the next 2 inputs blank, and choose the fre-cli branch to test

   b. If trying to merge from a fre-workflows fork: can skip first branch selection, input the fork name (ex: [user]/fre-workflows), input the fork's branch name, and choose the fre-cli branch to test

3. Click "Run workflow"

Note: you may need to reload the page to see your running workflow.

[ceblanton]

Yep, thanks!