Create .bazelversion to address postsubmit issues (#19089)

diff --git a/.bazelversion b/.bazelversion
new file mode 100644
index 0000000..024b066
--- /dev/null
+++ b/.bazelversion
@@ -0,0 +1 @@
+6.2.1
diff --git a/BUILD b/BUILD
index 0f8fdb6..c89d00f 100644
--- a/BUILD
+++ b/BUILD
@@ -40,7 +40,10 @@
         "//third_party:srcs",
         "//src/main/starlark/tests/builtins_bzl:srcs",
         "//src/main/java/com/google/devtools/build/docgen/release:srcs",
-    ] + glob([".bazelci/*"]) + [".bazelrc"],
+    ] + glob([".bazelci/*"]) + [
+        ".bazelrc",
+        ".bazelversion",
+    ],
     applicable_licenses = ["@io_bazel//:license"],
     visibility = ["//src/test/shell/bazel:__pkg__"],
 )