Bump io.papermc.paper:paper-api from 1.20.4-R0.1-SNAPSHOT to 1.20.6-R0.1-SNAPSHOT (#665)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -1,7 +1,7 @@
 [versions]
 jetbrains-annotations = "24.1.0"
 spigot = "1.20.6-R0.1-SNAPSHOT"
-paperSpigot = "1.20.4-R0.1-SNAPSHOT"
+paperSpigot = "1.20.6-R0.1-SNAPSHOT"
 junit = "5.10.2"
 mockito = "4.11.0"
 adventure-api = "4.16.0"