Bump docfx from 2.75.3 to 2.77.0 (#970)

Bumps [docfx](https://github.com/dotnet/docfx) from 2.75.3 to 2.77.0.
- [Release notes](https://github.com/dotnet/docfx/releases)
- [Changelog](https://github.com/dotnet/docfx/blob/main/RELEASENOTE.md)
- [Commits](dotnet/docfx@v2.75.3...v2.77.0)

---
updated-dependencies:
- dependency-name: docfx
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.config/dotnet-tools.json

@@ -15,7 +15,7 @@
       ]
     },
     "docfx": {
-      "version": "2.75.3",
+      "version": "2.77.0",
       "commands": [
         "docfx"
       ]