Upgrade default JDK to 25.

PiperOrigin-RevId: 947681426
Change-Id: I7ac6088148628c16ed2cb05ff0cc9b4d867376c5

toolchains/default_java_toolchain.bzl

diff --git a/toolchains/default_java_toolchain.bzl b/toolchains/default_java_toolchain.bzl
index f4f83f6..e4097ae 100644
--- a/toolchains/default_java_toolchain.bzl
+++ b/toolchains/default_java_toolchain.bzl
@@ -99,9 +99,7 @@
     reduced_classpath_incompatible_processors = [
         "dagger.hilt.processor.internal.root.RootProcessor",  # see b/21307381
     ],
-    # TODO: Update to JDK 25 after some time has passed - it no longer supports
-    # targeting JDK 7.
-    java_runtime = Label("//toolchains:remotejdk_21"),
+    java_runtime = Label("//toolchains:remotejdk_25"),
     oneversion = Label("//toolchains:one_version"),
 )