Fix Spring Boot 4.0 breaking changes for actuator modularization

Spring Boot 4.0 reorganized packages as part of its modularization effort.
This commit updates imports to use the new package locations:

- ConditionalOnEnabledHealthIndicator: moved to
  org.springframework.boot.health.autoconfigure.contributor
- MeterRegistryCustomizer: moved to
  org.springframework.boot.micrometer.metrics.autoconfigure
- Health and HealthIndicator: moved to
  org.springframework.boot.health.contributor

Also fixes Gradle DSL deprecation warning by using assignment syntax
for the group property.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: devondragon

build.gradle

@@ -14,7 +14,7 @@ plugins {
 import com.vanniktech.maven.publish.JavaLibrary
 import com.vanniktech.maven.publish.JavadocJar
 
-group 'com.digitalsanctuary.cf.turnstile'
+group = 'com.digitalsanctuary.cf.turnstile'
 // version '1.1.6-SNAPSHOT'
 description = 'SpringBoot Cloudflare Turnstile Library'
 

src/main/java/com/digitalsanctuary/cf/turnstile/TurnstileConfiguration.java

@@ -1,6 +1,6 @@
 package com.digitalsanctuary.cf.turnstile;
 
-import org.springframework.boot.actuate.autoconfigure.health.ConditionalOnEnabledHealthIndicator;
+import org.springframework.boot.health.autoconfigure.contributor.ConditionalOnEnabledHealthIndicator;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.context.annotation.Configuration;
@@ -70,7 +70,7 @@ static class TurnstileMetricsConfiguration {
      */
     @Configuration
     @ConditionalOnEnabledHealthIndicator("turnstile")
-    @ConditionalOnClass(name = "org.springframework.boot.actuate.health.HealthIndicator")
+    @ConditionalOnClass(name = "org.springframework.boot.health.contributor.HealthIndicator")
     @Import(TurnstileHealthIndicator.class)
     static class TurnstileHealthConfiguration {
     }

src/main/java/com/digitalsanctuary/cf/turnstile/config/TurnstileHealthIndicator.java

@@ -1,7 +1,7 @@
 package com.digitalsanctuary.cf.turnstile.config;
 
-import org.springframework.boot.actuate.health.Health;
-import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.health.contributor.Health;
+import org.springframework.boot.health.contributor.HealthIndicator;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.stereotype.Component;
 

src/main/java/com/digitalsanctuary/cf/turnstile/config/TurnstileMetricsConfig.java

@@ -1,6 +1,6 @@
 package com.digitalsanctuary.cf.turnstile.config;
 
-import org.springframework.boot.actuate.autoconfigure.metrics.MeterRegistryCustomizer;
+import org.springframework.boot.micrometer.metrics.autoconfigure.MeterRegistryCustomizer;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;