Update all-backend-non-major-dependencies (#2230)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

backend/build.gradle.kts

@@ -176,7 +176,7 @@ dependencies {
     // CVE-2022-4244
     implementation("org.codehaus.plexus:plexus-utils:4.0.2")
 
-    implementation(platform("software.amazon.awssdk:bom:2.28.15"))
+    implementation(platform("software.amazon.awssdk:bom:2.28.16"))
     implementation("software.amazon.awssdk:netty-nio-client")
     implementation("software.amazon.awssdk:s3")
 
@@ -185,7 +185,7 @@ dependencies {
 
     implementation("jakarta.mail:jakarta.mail-api:2.1.3")
     implementation("org.eclipse.angus:angus-mail:2.0.3")
-    implementation("com.icegreen:greenmail:2.1.0-rc-1")
+    implementation("com.icegreen:greenmail:2.1.0")
 
     // package served by private repo, requires authentication:
     implementation("de.bund.digitalservice:neuris-juris-xml-export:0.10.14") {