chore(deps): update dependency idna to v3.20

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
idna (changelog)	==3.19 → ==3.20

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Release Notes

kjd/idna (idna)

v3.20

Compare Source

• Update to Unicode 18.0.0.
• Better enforcement of the domain length limit in the incremental
  codec.
• Add support for Python 3.15.

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[claude]

LGTM, straightforward dependency pin bump.

What was reviewed: confirmed the diff is limited to bumping the transitive idna pin from 3.19 to 3.20 in requirements.txt and requirements-dev.txt; no source code, config, or other dependencies changed. The idna 3.20 release notes (Unicode 18.0.0 update, incremental codec length-limit enforcement, Python 3.15 support) don't indicate any breaking API changes relevant to this project's usage via requests.

Extended reasoning...

Overview

This PR touches only requirements.txt and requirements-dev.txt, bumping the pinned version of idna (a transitive dependency pulled in via requests) from 3.19 to 3.20. No application code, configuration, or CI files are modified.

Security risks

None identified. This is a patch-level bump of a well-known, widely-used IDNA encoding library. No new dependencies are introduced, no code paths change, and idna is not directly invoked by pyUSPTO's own code (it's used internally by requests/urllib3 for hostname handling).

Level of scrutiny

Low. This is exactly the kind of mechanical, automated dependency-pin update that should be approvable without deep human review: a single-line version change in two lockfile-style files, opened by Renovate, with no ambiguity about intent or scope.

Other factors

The change is fully self-contained (two-line diff across two files), matches the PR description exactly, and the upstream idna 3.20 changelog (Unicode 18.0.0 update, stricter domain-length enforcement, Python 3.15 support) contains nothing suggesting a breaking change relevant to this project's use of requests. No CODEOWNERS file exists to flag restricted paths, and there is no prior review history or outstanding objections on this PR to weigh against approval.