Add Google Drive upload for GitMetrics daily summary

[pvk-developer]

Description

Currently, there is a gap in the GitMetrics workflow: generated summary files are not consistently uploaded to Google Drive.

At the moment:

• The daily summary file (GitHub_Summary.xlsx, to be renamed gitmetrics_growth_summary.xlsx per Rename input / output Files #40 ) is not uploaded to Google Drive
• The only file available in Drive is the Consolidated Overview, which:
  • Does not include synthetic data libraries (e.g., sdv-dev and similar)
  • Does not provide full visibility into daily metrics

As a result, we need to access the summary via the GitHub Pages repository (assets/GitHub_Summary.xlsx), which is not ideal for accessibility.

This issue aims to automate the upload of the daily summary file to Google Drive.

### Proposed Solution
Extend the existing workflow to include a Google Drive upload step after generating the daily summary.