Avoid Gradle deprecation warnings

After the upgrade to Gradle 9.6.0/9.6.1, the Gradle build started
emitting warnings due to use of deprecated APIs.

For example, Project.getProperties() is now annotated as @⁠Deprecated
in Gradle 9.6 and will be removed in Gradle 10.0.

To avoid the warnings, this commit modifies:

- TestConventions to use `project.findProperty(...)` instead of
  `project.getProperties().get(...)`

- framework-api.gradle to use `rootProject.ext.moduleProjects` instead
  of simply `moduleProjects`

- framework-api.gradle and framework-bom.gradle to use
  `project(<projectX>)` instead of simply `<projectX>`

- ide.gradle so that it no longer uses the deprecated `javaRuntimeName`

See gh-36952

framework-api/framework-api.gradle

@@ -15,8 +15,8 @@ repositories {
 }
 
 dependencies {
-	moduleProjects.each { moduleProject ->
-		javadoc moduleProject
+	rootProject.ext.moduleProjects.each { moduleProject ->
+		javadoc project(moduleProject.path)
 	}
 }
 
@@ -52,7 +52,7 @@ javadoc {
 			// ensure the javadoc process can resolve types compiled from .aj sources
 			springAspectsOutput
 		)
-		classpath += files(moduleProjects.collect { it.sourceSets.main.compileClasspath })
+		classpath += files(rootProject.ext.moduleProjects.collect { it.sourceSets.main.compileClasspath })
 	}
 }
 
@@ -96,7 +96,7 @@ tasks.register('schemaZip', Zip) {
 	description = "Builds -${archiveClassifier} archive containing all " +
 			"XSDs for deployment at https://springframework.org/schema."
 	duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-	moduleProjects.each { module ->
+	rootProject.ext.moduleProjects.each { module ->
 		def Properties schemas = new Properties();
 
 		module.sourceSets.main.resources.find {