refactor: Updated 'upgrade requirements' workflow to use reusable workflows

[edx-requirements-bot]

Additional information from script execution

Python code cleanup by the cleanup-python-code Jenkins job.

This pull request was generated by the cleanup-python-code Jenkins job, which ran

cd .github/workflows;  TEAM_REVIEWERS=$(grep 'team-reviewers=' upgrade-python-requirements.yml -m 1 | awk '{print $2}'); TEAM_REVIEWERS=${TEAM_REVIEWERS/--team-reviewers=/}; SCHEDULE=$(grep 'cron:' upgrade-python-requirements.yml -m 1 | sed 's/^.*: //');   EMAIL_TO=$(grep 'to:' upgrade-python-requirements.yml -m 1 | sed 's/^.*: //'); [ -z $(grep 'Send success notification' upgrade-python-requirements.yml) ] && SEND_SUCCESS_NOTIFICATION=$(echo false) || SEND_SUCCESS_NOTIFICATION=$(echo true); : > upgrade-python-requirements.yml; printf "name: Upgrade Requirements\n\non:\n  schedule:\n     - cron: ${SCHEDULE}\n  workflow_dispatch:\n     inputs:\n       branch:\n         description: 'Target branch to create requirements PR against'\n         required: true\n         default: \$default-branch\njobs:\n   call-upgrade-python-requirements-workflow:\n    with:\n       branch: \${{ github.event.inputs.branch }}\n       team_reviewers: ${TEAM_REVIEWERS}\n       email_address: ${EMAIL_TO}\n       send_success_notification: ${SEND_SUCCESS_NOTIFICATION}\n    secrets:\n       requirements_bot_github_token: \${{ secrets.REQUIREMENTS_BOT_GITHUB_TOKEN }}\n       requirements_bot_github_email: \${{ secrets.REQUIREMENTS_BOT_GITHUB_EMAIL }}\n       edx_smtp_username: \${{ secrets.EDX_SMTP_USERNAME }}\n       edx_smtp_password: \${{ secrets.EDX_SMTP_PASSWORD }}\n    uses: edx/.github/.github/workflows/upgrade-python-requirements.yml@master\n" >> upgrade-python-requirements.yml;

The following packages were installed:
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[Ali-D-Akbar]

Just one concern from my side.

[Ali-D-Akbar]

Why're we not using ${{ github.event.inputs.branch || '$default-branch' }} here instead?

[Jawayria]

If branch isn't given as input, the default value for branch input will be used which is itself '$default-branch' so both would work fine.