Upgrade to Gradle 9.1

This commit upgrades the build to use Gradle 9.1.

To achieve that, the following changes were necessary.

- Stop using Groovy safe-navigation operator (?.) in
  framework-api.gradle due to a NullPointerException.

- Switch from the io.github.goooler.shadow plugin to the
  com.gradleup.shadow plugin, since the former is no longer maintained
  and the latter is a fork that replaces it.

Closes gh-35508

build.gradle

@@ -4,7 +4,7 @@ plugins {
 	id 'org.jetbrains.kotlin.plugin.serialization' version "${kotlinVersion}" apply false
 	id 'org.jetbrains.dokka'
 	id 'com.github.bjornvester.xjc' version '1.8.2' apply false
-	id 'io.github.goooler.shadow' version '8.1.8' apply false
+	id 'com.gradleup.shadow' version "9.1.0" apply false
 	id 'me.champeau.jmh' version '0.7.2' apply false
 	id 'io.spring.nullability' version '0.0.4' apply false
 }

framework-api/framework-api.gradle

@@ -98,9 +98,12 @@ tasks.register('schemaZip', Zip) {
 	moduleProjects.each { module ->
 		def Properties schemas = new Properties();
 
-		module.sourceSets.main.resources.find {
+		def schemaFile = module.sourceSets.main.resources.find {
 			(it.path.endsWith("META-INF/spring.schemas") || it.path.endsWith("META-INF\\spring.schemas"))
-		}?.withInputStream { schemas.load(it) }
+		}
+		if (schemaFile != null) {
+			schemaFile.withInputStream { schemas.load(it) }
+		}
 
 		for (def key : schemas.keySet()) {
 			def shortName = key.replaceAll(/http.*schema.(.*).spring-.*/, '$1')

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

gradlew

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 #
-# Copyright © 2015-2021 the original authors.
+# Copyright © 2015 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -114,7 +114,6 @@ case "$( uname )" in                #(
   NONSTOP* )        nonstop=true ;;
 esac
 
-CLASSPATH="\\\"\\\""
 
 
 # Determine the Java command to use to start the JVM.
@@ -172,7 +171,6 @@ fi
 # For Cygwin or MSYS, switch paths to Windows format before running java
 if "$cygwin" || "$msys" ; then
     APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
 
     JAVACMD=$( cygpath --unix "$JAVACMD" )
 
@@ -212,7 +210,6 @@ DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
         -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
         "$@"
 

gradlew.bat

@@ -70,11 +70,10 @@ goto fail
 :execute
 @rem Setup the command line
 
-set CLASSPATH=
 
 
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
 
 :end
 @rem End local scope for the variables with windows NT shell