Bump com.github.spotbugs-base from 6.0.19 to 6.0.21

Bumps com.github.spotbugs-base from 6.0.19 to 6.0.21.

---
updated-dependencies:
- dependency-name: com.github.spotbugs-base
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

gradle/libs.versions.toml

@@ -18,6 +18,6 @@ handy-tests = { group = "me.melontini", name = "handy-tests", version = "0.1.0-1
 [plugins]
 fabric-loom = { id = "fabric-loom", version = "1.6.12" }
 lombok = { id = "io.freefair.lombok", version = "8.6"}
-spotbugs-base = { id = "com.github.spotbugs-base", version = "6.0.19" }
+spotbugs-base = { id = "com.github.spotbugs-base", version = "6.0.21" }
 spotless = { id = "com.diffplug.spotless", version = "6.25.0" }
 modmuss50-publish = { id = "me.modmuss50.mod-publish-plugin", version = "0.6.3" }