[Y-build] Prepare builds for Java-26 BETA

Move tests to targeted Java version Java-26.

Also drop the second MacOS test configuration and add Y-build tests for
Windows instead.

Additionally fix the computation of the temurin download URL and fix
installing tools on Windows.

Author: HannesWell

JenkinsJobs/buildConfigurations.json

@@ -69,19 +69,18 @@
 		]
 	},
 	"Y": {
-		"typeName": "Beta Java 25",
+		"typeName": "Beta Java 26",
 		"folder": "YBuilds",
 		"streams": {
 			"4.38": {
 				"branch": "master",
-				"disabled": "true",
 				"schedule": "0 10 * 8-10 2,4,6\n0 10 1-26 11 2,4,6"
 			}
 		},
 		"branches": {
-			"eclipse.jdt.core": "BETA_JAVA25",
-			"eclipse.jdt.debug": "BETA_JAVA25",
-			"eclipse.jdt.ui": "BETA_JAVA25"
+			"eclipse.jdt.core": "BETA_JAVA26",
+			"eclipse.jdt.debug": "BETA_JAVA26",
+			"eclipse.jdt.ui": "BETA_JAVA26"
 		},
 		"mailingList": "[email protected]",
 		"testsFolder": "YBuilds",
@@ -101,44 +100,33 @@
 				"os": "linux",
 				"ws": "gtk",
 				"arch": "x86_64",
-				"javaVersion": 25,
+				"javaVersion": 26,
 				"agent": "ubuntu-2404",
 				"jdk": {
-					"type": "install",
-					"url": "https://download.java.net/java/GA/jdk25/bd75d5f9689641da8e1daabeccb5528b/36/GPL/openjdk-25_linux-x64_bin.tar.gz"
+					"type": "tool",
+					"name": "temurin-jdk26-latest"
 				}
 			},
 			{
 				"os": "macosx",
 				"ws": "cocoa",
 				"arch": "aarch64",
-				"javaVersion": 21,
-				"agent": "nc1ht-macos11-arm64",
-				"jdk": {
-					"type": "local",
-					"path": "/Library/Java/JavaVirtualMachines/jdk-21.0.5+11-arm64/Contents/Home"
-				}
-			},
-			{
-				"os": "macosx",
-				"ws": "cocoa",
-				"arch": "x86_64",
-				"javaVersion": 21,
+				"javaVersion": 26,
 				"agent": "nc1ht-macos11-arm64",
 				"jdk": {
-					"type": "local",
-					"path": "/Library/Java/JavaVirtualMachines/jdk-21.0.5+11/Contents/Home"
+					"type": "install",
+					"url": "https://download.java.net/java/early_access/jdk26/18/GPL/openjdk-26-ea+18_macos-aarch64_bin.tar.gz"
 				}
 			},
 			{
 				"os": "win32",
 				"ws": "win32",
 				"arch": "x86_64",
-				"javaVersion": 21,
+				"javaVersion": 26,
 				"agent": "qa6xd-win11",
 				"jdk": {
-					"type": "local",
-					"path": "C:\\Program Files\\Eclipse Adoptium\\jdk-21.0.5.11-hotspot"
+					"type": "install",
+					"url": "https://download.java.net/java/early_access/jdk26/18/GPL/openjdk-26-ea+18_windows-x64_bin.zip"
 				}
 			}
 		]