Bump com.vladsch.flexmark:flexmark from 0.62.2 to 0.64.8

Bumps [com.vladsch.flexmark:flexmark](https://github.com/vsch/flexmark-java) from 0.62.2 to 0.64.8.
- [Commits](https://github.com/vsch/flexmark-java/commits)

---
updated-dependencies:
- dependency-name: com.vladsch.flexmark:flexmark
  dependency-version: 0.64.8
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

build.gradle.kts

@@ -38,7 +38,7 @@ dependencies {
 
     implementation("com.twelvemonkeys.imageio:imageio-webp:3.12.0")
     implementation("com.jcraft:jsch:0.1.55")
-    implementation("com.vladsch.flexmark:flexmark:0.62.2")
+    implementation("com.vladsch.flexmark:flexmark:0.64.8")
     implementation("org.jline:jline:3.1.3")
     implementation("com.googlecode.soundlibs:vorbisspi:1.0.3.3")
     modCompileOnly("com.cinemamod:mcef:2.1.6-$mcefVer")