Bump springBoot.version from 2.4.2 to 2.7.3

Bumps `springBoot.version` from 2.4.2 to 2.7.3.

Updates `spring-boot-dependencies` from 2.4.2 to 2.7.3
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.4.2...v2.7.3)

Updates `spring-boot-maven-plugin` from 2.3.0.RELEASE to 2.7.3
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.3.0.RELEASE...v2.7.3)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-dependencies
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.springframework.boot:spring-boot-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -11,7 +11,7 @@
   <description>Spring Boot Application to deploy reactjs application.</description>
 
   <properties>
-    <springBoot.version>2.4.2</springBoot.version>
+    <springBoot.version>2.7.3</springBoot.version>
 
     <springBoot.maven.plugin.version>2.3.0.RELEASE</springBoot.maven.plugin.version>
     <maven.compiler.source>1.8</maven.compiler.source>
@@ -65,7 +65,7 @@
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-webflux</artifactId>
-        <version>2.2.6.RELEASE</version>
+        <version>2.7.3</version>
     </dependency>
 
     <dependency>