Use Tarski 1.42 and latest Giac, version bump

Author: kovzol

common/src/main/java/org/geogebra/common/GeoGebraConstants.java

@@ -14,7 +14,7 @@ public interface GeoGebraConstants {
 	/** complete version string */
 	public static final String VERSION_STRING = "5.0.641.0";
 	/** GeoGebra Discovery version string */
-	public static final String DISCOVERY_VERSION = "2026Apr18";
+	public static final String DISCOVERY_VERSION = "2026May23";
 
 	/** proper noun, should NOT be translated / transliterated */
 	public static final String APPLICATION_NAME = "GeoGebra";

gradle-scripts/versions.gradle

@@ -20,6 +20,6 @@ ext.hamcrestVersion = '2.2'
 // This is automatically updated when there is a new version of Giac out:
 //ext.javaGiacVersion = '69971'
 // Override this with an own compiled version:
-ext.javaGiacVersion = '20250926'
+ext.javaGiacVersion = '20260523'
 // Please don't change this line since the automatism looks for exact match.
-ext.javaTarskiVersion = '1.37_20260207'
+ext.javaTarskiVersion = '1.42_20260522'