Clear excessive output metadata in Jupyter Notebook (#126)

* 🧹 Clear excessive output metadata in Jupyter Notebook

- Cleared 'outputs' and 'execution_count' in all code cells.
- Removed 'colab' and 'outputId' metadata from cells.
- Removed global 'widgets' metadata from the notebook.
- Reduced file size of 'workbooks/exploring_httparchive-all-requests_tables.ipynb' from 575K to 18K.

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

* 🧹 Clear excessive output metadata from all Jupyter Notebooks

- Cleared 'outputs' and 'execution_count' in all code cells for all notebooks in 'workbooks/'.
- Removed 'colab', 'outputId', and 'executionInfo' metadata from cells.
- Removed global 'widgets' metadata to fix GitHub rendering errors.
- Significantly reduced file sizes for:
    - workbooks/exploring_httparchive-all-pages_tables.ipynb (1.4M -> 17K)
    - workbooks/exploring_httparchive-all-requests_tables.ipynb (575K -> 18K)
    - workbooks/exploring_pages_and_requests_tables_joined.ipynb (184K -> 12K)

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Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: max-ostapenko