build(deps): update tox requirement from >=3.9.0 to >=4.61.1

[dependabot]

Updates the requirements on tox to permit the latest version.

Release notes

Sourced from tox's releases.

v4.61.1

What's Changed

• 🐛 fix(schema): declare prefix in the labeled factor group's not clause by @​gaborbernat in tox-dev/tox#4051

Full Changelog: tox-dev/tox@4.61.0...4.61.1

Changelog

Sourced from tox's changelog.

Bug fixes - 4.61.1

• Publish a JSON Schema that compiles under SchemaStore's validator again, so editors pick up the configuration keys added since 4.56 - by :user:gaborbernat. (:issue:4051)

Contributor-facing changes - 4.61.1

• Check tox's JSON Schema with SchemaStore's own validator on every pull request that changes it, and again before the release sync opens a pull request there - by :user:gaborbernat. (:issue:4051)

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v4.61.0 (2026-08-28)

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Features - 4.61.0

• A labeled factor group can now declare a default for {factor:label} to fall back on when no factor of that group is active in the environment name. Setting TOX_FACTOR_<label> resolves that label to a given value for a single run - by :user:gaborbernat. (:issue:4045)
• A factor range now takes a label when you nest it under one, as in factors = [{ py_version = { prefix = "3.", start = 12, stop = 14 } }], which makes {factor:py_version} available for ranges - by :user:gaborbernat. (:issue:4046)

Bug fixes - 4.61.0

• Values passed via --override/-x or TOX_OVERRIDE now resolve substitutions such as {posargs}, {env:VAR} and {env_name}, instead of reaching the environment as literal text - by :user:gaborbernat. (:issue:4047)

Improved documentation - 4.61.0

• Point the virtualenv discovery link in the explanation documentation at its current location. (:issue:4042)

Contributor-facing changes - 4.61.0

• Replace the deprecated load_module call in the documentation configuration, which Python 3.15 removes - by :user:gaborbernat. (:issue:4043)

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v4.60.1 (2026-08-25)

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Bug fixes - 4.60.1

... (truncated)

Commits

• c8c010a release 4.61.1
• cd8c1fa 🐛 fix(schema): declare prefix in the labeled factor group's not clause (#4051)
• aa8f46c release 4.61.0
• 8ef0326 ✨ feat(toml): declare factor group defaults and per-run overrides (#4050)
• e489adb 🐛 fix(config): substitute inside override values (#4048)
• c1af929 ✨ feat(toml): allow labeling a range factor group (#4049)
• 930190c Replace deprecated load_module in docs conf (#4043)
• 2a4a215 docs: fix dead virtualenv discovery link in explanation.rst (#4042)
• e91ca3b release 4.60.1
• 59e984f Report an empty TOML command value as a handled error (#4041)
• Additional commits viewable in compare view

[dependabot]

Superseded by #206.