chore(deps): bump bazel to 9

.bazelversion

diff --git a/.bazelversion b/.bazelversion
index e8be684..881ed57 100644
--- a/.bazelversion
+++ b/.bazelversion
@@ -1 +1 @@
-7.6.1
+9.0.0rc1

.github/workflows/ci.yaml

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 7ecd22d..dc3149f 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -141,7 +141,7 @@
                     # and remove the need for bazel 6 workspace support for local development.
                     - bazel-version:
                           major: 6
-                      bzlmod: 0
+                      folder: .
                     # Don't run workspace tests unit tests.
                     - bzlmod: 0
                       folder: .