Specify mainCapabilityAttribute for paper-api

Fixes the api being bundled into com.destroystokyo.paper as paper-mojangapi

patches/api/0466-Brigadier-based-command-API.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Brigadier based command API
 Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>
 
 diff --git a/build.gradle.kts b/build.gradle.kts
-index 4da053d427f3f9c5e7fc144408836ebef80026c6..540fe7e2c110e79c3742f229b3ed8c54b101d260 100644
+index 4da053d427f3f9c5e7fc144408836ebef80026c6..a82bc1a12db5531c4c8ade8e6582cf2d5c35fd56 100644
 --- a/build.gradle.kts
 +++ b/build.gradle.kts
 @@ -27,6 +27,7 @@ configurations.api {
@@ -17,18 +17,22 @@ index 4da053d427f3f9c5e7fc144408836ebef80026c6..540fe7e2c110e79c3742f229b3ed8c54
      // api dependencies are listed transitively to API consumers
      api("com.google.guava:guava:32.1.2-jre")
      api("com.google.code.gson:gson:2.10.1")
-@@ -92,9 +93,29 @@ sourceSets {
+@@ -92,9 +93,33 @@ sourceSets {
      }
  }
  // Paper end
 +// Paper start - brigadier API
 +val outgoingVariants = arrayOf("runtimeElements", "apiElements", "sourcesElements", "javadocElements")
++val mainCapability = "${project.group}:${project.name}:${project.version}"
 +configurations {
 +    val outgoing = outgoingVariants.map { named(it) }
 +    for (config in outgoing) {
 +        config {
++            attributes {
++                attribute(io.papermc.paperweight.util.mainCapabilityAttribute, mainCapability)
++            }
 +            outgoing {
-+                capability("${project.group}:${project.name}:${project.version}")
++                capability(mainCapability)
 +                capability("io.papermc.paper:paper-mojangapi:${project.version}")
 +                capability("com.destroystokyo.paper:paper-mojangapi:${project.version}")
 +            }