Update scalafmt-core to 3.9.9 (#12)

## About this PR
📦 Updates
[org.scalameta:scalafmt-core](https://github.com/scalameta/scalafmt)
from `3.9.8` to `3.9.9`

📜 [GitHub Release
Notes](https://github.com/scalameta/scalafmt/releases/tag/v3.9.9) -
[Version
Diff](scalameta/scalafmt@v3.9.8...v3.9.9)

## Usage
✅ **Please merge!**

I'll automatically update this PR to resolve conflicts as long as you
don't change it yourself.

If you'd like to skip this version, you can just close this PR. If you
have any feedback, just mention me in the comments below.

Configure Scala Steward for your repository with a
[`.scala-steward.conf`](https://github.com/scala-steward-org/scala-steward/blob/aa89f0da1e565ff940bddae9287eeb474b0d610f/docs/repo-specific-configuration.md)
file.

_Have a fantastic day writing Scala!_

<details>
<summary>⚙ Adjust future updates</summary>

Add this to your `.scala-steward.conf` file to ignore future updates of
this dependency:
```
updates.ignore = [ { groupId = "org.scalameta", artifactId = "scalafmt-core" } ]
```
Or, add this to slow down future updates of this dependency:
```
dependencyOverrides = [{
  pullRequests = { frequency = "30 days" },
  dependency = { groupId = "org.scalameta", artifactId = "scalafmt-core" }
}]
```
</details>

<sup>
labels: library-update, early-semver-patch, semver-spec-patch,
commit-count:1
</sup>

<!-- scala-steward = {
  "Update" : {
    "ForArtifactId" : {
      "crossDependency" : [
        {
          "groupId" : "org.scalameta",
          "artifactId" : {
            "name" : "scalafmt-core",
            "maybeCrossName" : "scalafmt-core_2.13"
          },
          "version" : "3.9.8",
          "sbtVersion" : null,
          "scalaVersion" : null,
          "configurations" : null
        }
      ],
      "newerVersions" : [
        "3.9.9"
      ],
      "newerGroupId" : null,
      "newerArtifactId" : null
    }
  },
  "Labels" : [
    "library-update",
    "early-semver-patch",
    "semver-spec-patch",
    "commit-count:1"
  ]
} -->

Author: scala-steward

.scalafmt.conf

@@ -3,7 +3,7 @@
 # - better interop with default IntelliJ IDEA setup (matching import and modifiers sorting logic)
 # - better developer experience on laptop screens (like 16' MBPs) with IntelliJ IDEA (line wraps)
 
-version = 3.9.8
+version = 3.9.9
 
 runner.dialect = scala213source3
 fileOverride {