Update Spring Boot version to 4.1.2 (#463)

Author: rashidi

docs/modules/ROOT/pages/index.adoc

@@ -20,4 +20,5 @@ best practices and keeping all dependencies up-to-date. The quality of these tut
 and always will be, my primary goal.
 
 With the help of https://github.com/dependabot[Dependabot], each tutorial is also kept up-to-date with the latest
-dependencies. Currently, we are using Java https://adoptium.net/en-GB/temurin/releases/?version=25[Temurin 25]
+dependencies. Currently, we are using Java https://adoptium.net/en-GB/temurin/releases/?version=25[Temurin 25] 
+with https://plugins.gradle.org/plugin/org.springframework.boot/4.1.2[Spring Boot 4.1.2]

supplemental-ui/partials/footer-content.hbs

@@ -3,7 +3,7 @@
     <p class="footer-brand">Spring Boot Tutorials by <a href="https://about.me/rashidi.zin">Rashidi Zin</a></p>
     <p id="badges">
       <img alt="Java version" src="https://img.shields.io/badge/Java-25-6db33f?style=flat-square&logo=openjdk&logoColor=white" />
-      <img alt="Spring Boot version" src="https://img.shields.io/badge/Spring_Boot-4.1.1-6db33f?style=flat-square&logo=springboot&logoColor=white" />
+      <img alt="Spring Boot version" src="https://img.shields.io/badge/Spring_Boot-4.1.2-6db33f?style=flat-square&logo=springboot&logoColor=white" />
       <img alt="License - Unlicense" src="https://img.shields.io/github/license/rashidi/spring-boot-tutorials?style=flat-square&color=334155" />
     </p>
   </div>