Support Bazel 8, sans bzlmod (#68)

After updating `rules_java` appropriately, we can unblock Bazel 8
support when using `WORKSPACE` mode and no bzlmod. This is the first
step towards bzlmod support.

Author: jchadwick-buf

.bazelrc

@@ -1,4 +1,4 @@
-common --noenable_bzlmod
+common --noenable_bzlmod --enable_workspace
 
 build --cxxopt=-std=c++17 --host_cxxopt=-std=c++17
 build --cxxopt=-fsized-deallocation

.bazelversion

@@ -1 +1 @@
-7.4.0
+8.0.0

WORKSPACE

@@ -4,12 +4,10 @@ load("//bazel:deps.bzl", "protovalidate_cc_dependencies")
 
 protovalidate_cc_dependencies()
 
-load("@rules_java//java:repositories.bzl", "rules_java_dependencies", "rules_java_toolchains")
+load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")
 
 rules_java_dependencies()
 
-rules_java_toolchains()
-
 load("@rules_python//python:repositories.bzl", "py_repositories")
 
 py_repositories()
@@ -18,6 +16,10 @@ load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 
 protobuf_deps()
 
+load("@rules_java//java:repositories.bzl", "rules_java_toolchains")
+
+rules_java_toolchains()
+
 load("@rules_buf//buf:repositories.bzl", "rules_buf_dependencies", "rules_buf_toolchains")
 
 rules_buf_dependencies()

bazel/deps.bzl

@@ -36,9 +36,9 @@ _dependencies = {
         ],
     },
     "rules_java": {
-        "sha256": "c0ee60f8757f140c157fc2c7af703d819514de6e025ebf70386d38bdd85fce83",
+        "sha256": "b0b8b7b2cfbf575112acf716ec788847929f322efa5c34195eb12a43d1df7e5c",
         "urls": [
-            "https://github.com/bazelbuild/rules_java/releases/download/7.12.3/rules_java-7.12.3.tar.gz"
+            "https://github.com/bazelbuild/rules_java/releases/download/8.7.2/rules_java-8.7.2.tar.gz"
         ],
     },
     "rules_python": {