Bump solargraph from 0.38.3 to 0.38.4 (#163)

Bumps [solargraph](https://github.com/castwide/solargraph) from 0.38.3 to 0.38.4.
- [Release notes](https://github.com/castwide/solargraph/releases)
- [Commits](castwide/solargraph@v0.38.3...v0.38.4)

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

Gemfile.lock

@@ -198,7 +198,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    solargraph (0.38.3)
+    solargraph (0.38.4)
       backport (~> 1.1)
       benchmark
       bundler (>= 1.17.2)