Update samples to Spring Security 7.0.0-SNAPSHOT

Closes gh-2090

samples/backend-for-spa-client/gradle.properties

@@ -1 +1 @@
-spring-security.version=6.3.7
+spring-security.version=7.0.0-SNAPSHOT

samples/default-authorizationserver/gradle.properties

@@ -1 +1 @@
-spring-security.version=6.5.0-M2
+spring-security.version=7.0.0-SNAPSHOT

samples/demo-authorizationserver/gradle.properties

@@ -1 +1 @@
-spring-security.version=6.5.0-M2
+spring-security.version=7.0.0-SNAPSHOT

samples/demo-client/gradle.properties

@@ -1 +1 @@
-spring-security.version=6.3.7
+spring-security.version=7.0.0-SNAPSHOT

samples/messages-resource/gradle.properties

@@ -1 +1 @@
-spring-security.version=6.3.7
+spring-security.version=7.0.0-SNAPSHOT

samples/users-resource/gradle.properties

@@ -1 +1 @@
-spring-security.version=6.3.7
+spring-security.version=7.0.0-SNAPSHOT