update springboot 2.7.14 => 2.7.15

pom.xml

@@ -14,7 +14,7 @@
 
     <properties>
         <ruoyi-vue-plus.version>4.8.0</ruoyi-vue-plus.version>
-        <spring-boot.version>2.7.14</spring-boot.version>
+        <spring-boot.version>2.7.15</spring-boot.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.8</java.version>