[Merged by Bors] - feat: the one-line-align linter

[adomani]

This linter makes sure that #align statements span a single line.

---

[github-actions]

PR summary 6833d4867b

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ getLinterOneLineAlign
+ oneLineAlign
+ toAlign

You can run this locally as follows

## summary with just the declaration names:
./scripts/no_lost_declarations.sh short <optional_commit>

## more verbose report:
./scripts/no_lost_declarations.sh <optional_commit>

[grunweg]

The implementation looks good (two trivial comments); thanks for writing it.

I think this linter can be added as long as the aligns still exist (and be removed with them). I don't have a strong opinion on this point - let's see what the broader opinion is.
maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by grunweg.

[github-actions]

🚀 Pull request has been placed on the maintainer queue by grunweg.

[jcommelin]

Thanks 🎉

bors merge

[mathlib-bors]

Build failed (retrying...):

• Build

[mathlib-bors]

Build failed:

• Build

[grunweg]

Can you merge master, please? I don't see why this should fail anything...

[adomani]

I think that it was conflicted with a section end in a test file.

[mattrobball]

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

• Build
• Lint style