Update dependency Sphinx to v4.1.2

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
Sphinx (source)	==4.1.1 -> ==4.1.2

---

Release Notes

sphinx-doc/sphinx

### [`v4.1.2`](https://togithub.com/sphinx-doc/sphinx/blob/master/CHANGES#Release-412-released-Jul-27-2021) [Compare Source](https://togithub.com/sphinx-doc/sphinx/compare/v4.1.1...v4.1.2) \===================================== ## Incompatible changes - [#​9435](https://togithub.com/sphinx-doc/sphinx/issues/9435): linkcheck: Disable checking automatically generated anchors on github.com (ex. anchors in reST/Markdown documents) ## Bugs fixed - [#​9489](https://togithub.com/sphinx-doc/sphinx/issues/9489): autodoc: Custom types using `typing.NewType` are not displayed well with the HEAD of 3.10 - [#​9490](https://togithub.com/sphinx-doc/sphinx/issues/9490): autodoc: Some objects under `typing` module are not displayed well with the HEAD of 3.10 - [#​9436](https://togithub.com/sphinx-doc/sphinx/issues/9436), [#​9471](https://togithub.com/sphinx-doc/sphinx/issues/9471): autodoc: crashed if `autodoc_class_signature = "separated"` - [#​9456](https://togithub.com/sphinx-doc/sphinx/issues/9456): html search: html_copy_source can't control the search summaries - [#​9435](https://togithub.com/sphinx-doc/sphinx/issues/9435): linkcheck: Failed to check anchors in github.com

---

Configuration

📅 Schedule: At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box.

---

This PR has been generated by WhiteSource Renovate. View repository job log here.

[coveralls]

Coverage remained the same at 88.829% when pulling da4fc61130621ea761ae8182fa4fa1e02cdf6435 on renovate/sphinx-4.x into b420fa15598a279a9debd7e1e2756ef2c0e60ccb on develop.