Add nio-multipart-parser to webflux starter

This library is required for parsing multipart requests asynchronously
in Spring WebFlux. Framework treats this as an optional dependency, but
Boot auto-configures multipart support with Servlet by default.

Closes gh-10073

spring-boot-dependencies/pom.xml

@@ -138,6 +138,7 @@
 		<nekohtml.version>1.9.22</nekohtml.version>
 		<neo4j-ogm.version>3.0.0-RC1</neo4j-ogm.version>
 		<netty.version>4.1.13.Final</netty.version>
+		<nio-multipart-parser.version>1.0.0</nio-multipart-parser.version>
 		<postgresql.version>42.1.3</postgresql.version>
 		<quartz.version>2.3.0</quartz.version>
 		<querydsl.version>4.1.4</querydsl.version>
@@ -2412,6 +2413,11 @@
 					</exclusion>
 				</exclusions>
 			</dependency>
+			<dependency>
+				<groupId>org.synchronoss.cloud</groupId>
+				<artifactId>nio-multipart-parser</artifactId>
+				<version>${nio-multipart-parser.version}</version>
+			</dependency>
 			<dependency>
 				<groupId>org.xerial</groupId>
 				<artifactId>sqlite-jdbc</artifactId>

spring-boot-starters/spring-boot-starter-webflux/pom.xml

@@ -43,5 +43,9 @@
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-webflux</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.synchronoss.cloud</groupId>
+			<artifactId>nio-multipart-parser</artifactId>
+		</dependency>
 	</dependencies>
 </project>