Update the compilation JDK to 25 (#323)

This is necessary to support `--java_runtime_version=remotejdk_25` with lower `--java_language_version` values. JDK 21 already showed warnings when targeting Java 8.

Closes #323

COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_java/pull/323 from fmeum:jdk-25-default 8ab1d01eac01fcb221af113ede41fc7cdbac2581
PiperOrigin-RevId: 810400625
Change-Id: Id7b66c2a737f28b09316077a338ec9dd0e1928e1

toolchains/BUILD

diff --git a/toolchains/BUILD b/toolchains/BUILD
index d6d18bc..3209930 100644
--- a/toolchains/BUILD
+++ b/toolchains/BUILD
@@ -358,7 +358,7 @@
 [
     default_java_toolchain(
         name = ("toolchain_java%d" if release <= 11 else "toolchain_jdk_%d") % release,
-        configuration = DEFAULT_TOOLCHAIN_CONFIGURATION if release <= 21 else DEFAULT_TOOLCHAIN_CONFIGURATION | {"java_runtime": ":remotejdk_%d" % release},
+        configuration = DEFAULT_TOOLCHAIN_CONFIGURATION | {"java_runtime": ":remotejdk_25"},
         source_version = "%s" % release,
         target_version = "%s" % release,
     )

toolchains/default_java_toolchain.bzl

diff --git a/toolchains/default_java_toolchain.bzl b/toolchains/default_java_toolchain.bzl
index 4ec8961..4f46393 100644
--- a/toolchains/default_java_toolchain.bzl
+++ b/toolchains/default_java_toolchain.bzl
@@ -98,6 +98,8 @@
     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"),
     oneversion = Label("//toolchains:one_version"),
 )