Simplify CORS handling

This makes caching simpler to reason about (no Vary header) and more
efficient (also because there is no Vary header).

Signed-off-by: Graham <gpe@openrs2.org>

archive/src/main/kotlin/org/openrs2/archive/web/WebServer.kt

@@ -2,7 +2,9 @@ package org.openrs2.archive.web
 
 import com.fasterxml.jackson.databind.ObjectMapper
 import io.ktor.http.ContentType
+import io.ktor.http.HttpHeaders
 import io.ktor.serialization.jackson.JacksonConverter
+import io.ktor.server.application.*
 import io.ktor.server.application.ApplicationCall
 import io.ktor.server.application.call
 import io.ktor.server.application.install
@@ -14,9 +16,9 @@ import io.ktor.server.plugins.autohead.AutoHeadResponse
 import io.ktor.server.plugins.cachingheaders.CachingHeaders
 import io.ktor.server.plugins.conditionalheaders.ConditionalHeaders
 import io.ktor.server.plugins.contentnegotiation.ContentNegotiation
-import io.ktor.server.plugins.cors.routing.CORS
 import io.ktor.server.plugins.defaultheaders.DefaultHeaders
 import io.ktor.server.plugins.forwardedheaders.XForwardedHeaders
+import io.ktor.server.response.header
 import io.ktor.server.response.respond
 import io.ktor.server.response.respondRedirect
 import io.ktor.server.routing.get
@@ -44,9 +46,11 @@ public class WebServer @Inject constructor(
             install(CachingHeaders)
             install(ConditionalHeaders)
 
-            install(CORS) {
-                anyHost()
-            }
+            install(createApplicationPlugin(name = "CORS") {
+                onCall { call ->
+                    call.response.header(HttpHeaders.AccessControlAllowOrigin, "*")
+                }
+            })
 
             install(ContentNegotiation) {
                 ignoreType<ThymeleafContent>()

gradle/libs.versions.toml

@@ -62,7 +62,6 @@ ktor-server-autoHeadResponse = { module = "io.ktor:ktor-server-auto-head-respons
 ktor-server-cachingHeaders = { module = "io.ktor:ktor-server-caching-headers", version.ref = "ktor" }
 ktor-server-conditionalHeaders = { module = "io.ktor:ktor-server-conditional-headers", version.ref = "ktor" }
 ktor-server-contentNegotiation = { module = "io.ktor:ktor-server-content-negotiation", version.ref = "ktor" }
-ktor-server-cors = { module = "io.ktor:ktor-server-cors", version.ref = "ktor" }
 ktor-server-defaultHeaders = { module = "io.ktor:ktor-server-default-headers", version.ref = "ktor" }
 ktor-server-forwardedHeader = { module = "io.ktor:ktor-server-forwarded-header", version.ref = "ktor" }
 ktor-server-jetty = { module = "io.ktor:ktor-server-jetty", version.ref = "ktor" }
@@ -95,7 +94,6 @@ ktor = [
 	"ktor-server-cachingHeaders",
 	"ktor-server-conditionalHeaders",
 	"ktor-server-contentNegotiation",
-	"ktor-server-cors",
 	"ktor-server-defaultHeaders",
 	"ktor-server-forwardedHeader",
 	"ktor-server-jetty",