build(deps-dev): bump ex_doc from 0.30.7 to 0.30.8

Bumps [ex_doc](https://github.com/elixir-lang/ex_doc) from 0.30.7 to 0.30.8.
- [Changelog](https://github.com/elixir-lang/ex_doc/blob/main/CHANGELOG.md)
- [Commits](elixir-lang/ex_doc@v0.30.7...v0.30.8)

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

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

mix.lock

@@ -7,7 +7,7 @@
   "cowlib": {:hex, :cowlib, "2.11.0", "0b9ff9c346629256c42ebe1eeb769a83c6cb771a6ee5960bd110ab0b9b872063", [:make, :rebar3], [], "hexpm", "2b3e9da0b21c4565751a6d4901c20d1b4cc25cbb7fd50d91d2ab6dd287bc86a9"},
   "earmark": {:hex, :earmark, "1.4.4", "4821b8d05cda507189d51f2caeef370cf1e18ca5d7dfb7d31e9cafe6688106a4", [:mix], [], "hexpm", "1f93aba7340574847c0f609da787f0d79efcab51b044bb6e242cae5aca9d264d"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.37", "2ad73550e27c8946648b06905a57e4d454e4d7229c2dafa72a0348c99d8be5f7", [:mix], [], "hexpm", "6b19783f2802f039806f375610faa22da130b8edc21209d0bff47918bb48360e"},
-  "ex_doc": {:hex, :ex_doc, "0.30.7", "dc7247091aec738ab781f71cbebfc07979d1040c98c7ee67dbde99b7829b743d", [:mix], [{:earmark_parser, "~> 1.4.31", [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", "868ff1c7a44c462741853840d1e7ef19a07906e7467cb8da070c158ea6a42a51"},
+  "ex_doc": {:hex, :ex_doc, "0.30.8", "cf3eb2eb32137966aab0929bb3af42773b2d08e2f785a5fee9caabf664082cb3", [:mix], [{:earmark_parser, "~> 1.4.31", [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", "bfb981d8e0a8ab23857e502d611c612ae2c24536dd3b530e741d1d94ea44e6e2"},
   "hackney": {:hex, :hackney, "1.15.2", "07e33c794f8f8964ee86cebec1a8ed88db5070e52e904b8f12209773c1036085", [:rebar3], [{:certifi, "2.5.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "6.0.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.5", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm", "e0100f8ef7d1124222c11ad362c857d3df7cb5f4204054f9f0f4a728666591fc"},
   "hpax": {:hex, :hpax, "0.1.2", "09a75600d9d8bbd064cdd741f21fc06fc1f4cf3d0fcc335e5aa19be1a7235c84", [:mix], [], "hexpm", "2c87843d5a23f5f16748ebe77969880e29809580efdaccd615cd3bed628a8c13"},
   "idna": {:hex, :idna, "6.0.0", "689c46cbcdf3524c44d5f3dde8001f364cd7608a99556d8fbd8239a5798d4c10", [:rebar3], [{:unicode_util_compat, "0.4.1", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "4bdd305eb64e18b0273864920695cb18d7a2021f31a11b9c5fbcd9a253f936e2"},