Update spring boot to v2.7.3

Author: renovate[bot]

pom.xml

@@ -72,7 +72,7 @@
     <mybatis-freemarker.version>1.2.3</mybatis-freemarker.version>
     <mybatis-velocity.version>2.1.1</mybatis-velocity.version>
     <mybatis-thymeleaf.version>1.0.3</mybatis-thymeleaf.version>
-    <spring-boot.version>2.7.2</spring-boot.version>
+    <spring-boot.version>2.7.3</spring-boot.version>
   </properties>
 
   <build>