Bump ex_doc from 0.28.5 to 0.28.6 (#428)

Bumps [ex_doc](https://github.com/elixir-lang/ex_doc) from 0.28.5 to 0.28.6.
- [Release notes](https://github.com/elixir-lang/ex_doc/releases)
- [Changelog](https://github.com/elixir-lang/ex_doc/blob/main/CHANGELOG.md)
- [Commits](elixir-lang/ex_doc@v0.28.5...v0.28.6)

---
updated-dependencies:
- dependency-name: ex_doc
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

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

mix.lock

@@ -9,7 +9,7 @@
   "earmark_parser": {:hex, :earmark_parser, "1.4.28", "0bf6546eb7cd6185ae086cbc5d20cd6dbb4b428aad14c02c49f7b554484b4586", [:mix], [], "hexpm", "501cef12286a3231dc80c81352a9453decf9586977f917a96e619293132743fb"},
   "elixir_make": {:hex, :elixir_make, "0.6.3", "bc07d53221216838d79e03a8019d0839786703129599e9619f4ab74c8c096eac", [:mix], [], "hexpm", "f5cbd651c5678bcaabdbb7857658ee106b12509cd976c2c2fca99688e1daf716"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
-  "ex_doc": {:hex, :ex_doc, "0.28.5", "3e52a6d2130ce74d096859e477b97080c156d0926701c13870a4e1f752363279", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "d2c4b07133113e9aa3e9ba27efb9088ba900e9e51caa383919676afdf09ab181"},
+  "ex_doc": {:hex, :ex_doc, "0.28.6", "2bbd7a143d3014fc26de9056793e97600ae8978af2ced82c2575f130b7c0d7d7", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "bca1441614654710ba37a0e173079273d619f9160cbcc8cd04e6bd59f1ad0e29"},
   "fast_html": {:hex, :fast_html, "2.0.5", "c61760340606c1077ff1f196f17834056cb1dd3d5cb92a9f2cabf28bc6221c3c", [:make, :mix], [{:elixir_make, "~> 0.4", [hex: :elixir_make, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 0.2.0", [hex: :nimble_pool, repo: "hexpm", optional: false]}], "hexpm", "605f4f4829443c14127694ebabb681778712ceecb4470ec32aa31012330e6506"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
   "html5ever": {:hex, :html5ever, "0.14.0", "a42762469dcba564a8986dce688f911913dd056221bcf11464bb14c6f262e29a", [:mix], [{:rustler, ">= 0.0.0", [hex: :rustler, repo: "hexpm", optional: true]}, {:rustler_precompiled, "~> 0.5.2", [hex: :rustler_precompiled, repo: "hexpm", optional: false]}], "hexpm", "09b73075a8a1b0936f0484ec34309332e59d74549c94f75ed41624259950092d"},