Enable reading from the remote build cache for all

Previously, the remote build cache was only enabled if the
GRADLE_ENTERPRISE_URL environment variable was configured. This meant
that contributors would not benefit from the build time improvements
of the caching without some additional setup.

This commit updates the buildCache configuration so that reading from
the remote build cache at https://ge.spring.io is enabled for all.
Pushing to the cache continues to be disabled unless the required
credentials are provided. Build scan configuration has also been
updated in line with this change. While the server URL is now
hardcoded, publishing is still opt-in via an environment variable.
The exact mechanism by which someone can opt in will change in the
future once some server-side changes have been made. At this point,
only a change to publishAlwaysIf should be necessary.

Closes gh-24105

build.gradle

@@ -18,16 +18,14 @@ plugins {
 	id "com.github.ben-manes.versions" version "0.24.0"
 }
 
-if (System.getenv('GRADLE_ENTERPRISE_URL')) {
-	apply from: "$rootDir/gradle/build-scan-user-data.gradle"
-	buildScan {
-		captureTaskInputFiles = true
-		obfuscation {
-			ipAddresses { addresses -> addresses.collect { address -> '0.0.0.0'} }
-		}
-		publishAlways()
-		server = System.getenv('GRADLE_ENTERPRISE_URL')
+apply from: "$rootDir/gradle/build-scan-user-data.gradle"
+buildScan {
+	captureTaskInputFiles = true
+	obfuscation {
+		ipAddresses { addresses -> addresses.collect { address -> '0.0.0.0'} }
 	}
+	publishAlwaysIf(System.getenv('GRADLE_ENTERPRISE_URL') != null)
+	server = 'https://ge.spring.io'
 }
 
 ext {

gradle/build-cache-settings.gradle

@@ -2,18 +2,16 @@ buildCache {
 	local {
 		enabled = true
 	}
-	if (System.getenv('GRADLE_ENTERPRISE_URL')) {
-		remote(HttpBuildCache) {
-			enabled = true
-			url = "${System.getenv('GRADLE_ENTERPRISE_URL')}/cache/"
-			def cacheUsername = System.getenv('GRADLE_ENTERPRISE_CACHE_USERNAME')
-			def cachePassword = System.getenv('GRADLE_ENTERPRISE_CACHE_PASSWORD')
-			if (cacheUsername && cachePassword) {
-				push = true
-				credentials {
-					username = cacheUsername
-					password = cachePassword
-				}
+	remote(HttpBuildCache) {
+		enabled = true
+		url = 'https://ge.spring.io/cache/'
+		def cacheUsername = System.getenv('GRADLE_ENTERPRISE_CACHE_USERNAME')
+		def cachePassword = System.getenv('GRADLE_ENTERPRISE_CACHE_PASSWORD')
+		if (cacheUsername && cachePassword) {
+			push = true
+			credentials {
+				username = cacheUsername
+				password = cachePassword
 			}
 		}
 	}