DOC: Add tzdata to dependencies section in README

[n-dett]

Pandas version checks

• I have checked that the issue still exists on the latest versions of the docs on main here

Location of the documentation

https://github.com/pandas-dev/pandas/blob/main/README.md

Documentation problem

tzdata is listed as a required dependency in the installation documentation, but is not listed with the other required dependencies in the README.

Suggested fix for documentation

Add tzdata to the list of dependencies in the README so that the README matches the most current and accurate documentation. I intend to work on this issue.

[n-dett]

take