Provide a way to randomize retry times

[sethgupton-mastery]

Describe the bug
We have a thundering herd problem where a bunch of workflows come in at the same time and need to commit to the same file. They all come in, one succeeds and the rest fail, they wait for retry_wait_seconds, one more succeeds and the rest fail... Repeat until only max_attempts succeeds and the rest fail.

Expected behavior
Add ability to add some randomness to the retry_wait_seconds.

[sethgupton-mastery]

P.S. We are solving this in a different way right now. But it would be nice to have it built in.

- name: Generate random retry_wait_seconds
  id: randomize-retry
  run: |          
   random_retry_wait=$((5 + RANDOM % 16))
   echo "Random retry wait time: $random_retry_wait seconds"
   echo "retry_wait_seconds=$random_retry_wait" >> $GITHUB_ENV

- name: Commit updates
  uses: nick-fields/retry@v2.8.3
  with:
   timeout_minutes: 2
   retry_on: any
   retry_wait_seconds: ${{ env.retry_wait_seconds }}
   max_attempts: 10
   command: |