Bump io.papermc.paper:paper-api

Bumps io.papermc.paper:paper-api from 1.17.1-R0.1-SNAPSHOT to 1.20.4-R0.1-SNAPSHOT.

---
updated-dependencies:
- dependency-name: io.papermc.paper:paper-api
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 # Platforms
-minecraft = "1.17.1-R0.1-SNAPSHOT"
+minecraft = "1.20.4-R0.1-SNAPSHOT"
 
 # Libraries
 cloud = "1.8.4"