Add uri to require list for ruby 3.4

[getty104]

Ruby 3.4 does not support uri modules by default.
This PR is for adopting this update.

Ref

https://github.com/increments/qiita-markdown/actions/runs/7704576731/job/20997185179?pr=153

# NameError:
#   uninitialized constant Qiita::Markdown::Transformers::FilterIframe::URI
#   ./lib/qiita/markdown/transformers/filter_iframe.rb:46:in `host_of'

[codeclimate]

Code Climate has analyzed commit 1c189a1 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (80% is the threshold).

This pull request will bring the total coverage in the repository to 98.9% (0.0% change).

View more on Code Climate.

[wataru86]

LGTM!