Use correct attribution in the footer of documentation pages

To be inline with ASF policy, we should update the text in the footer used in the docs (e.g. https://arrow.apache.org/adbc/current/index.html) to match the footer used in the main website (https://arrow.apache.org/). i.e. add the trademark attribution test.

Compare the footer on the ADBC documentation page at arrow.apache.org/adbc/current/index.html with the footer on the main site at arrow.apache.org/. Locate the source that supplies the documentation footer, update its attribution to match the ASF-required wording, and verify the generated documentation page shows the same attribution.

Written by the indexing model from the issue text.