extensions: Separate generation of extension db from docs in CI (#15117)

Moved the db generation into a bazel job - which will allow other tasks that also require this data to make use of it more easily/bazely

this also adds buildozer into the bazel env, so we might want to make use of that elsewhere and potentially remove buildozer from the build-image env

Touch #13229

Signed-off-by: Ryan Northey <ryan@synca.io>

Mirrored from https://github.com/envoyproxy/envoy @ a03209d5caf77b36ca4c40671ade8e328cb93fad

bazel/repositories.bzl

@@ -22,6 +22,9 @@ def api_dependencies():
     external_http_archive(
         name = "com_google_googleapis",
     )
+    external_http_archive(
+        name = "com_github_bazelbuild_buildtools",
+    )
     external_http_archive(
         name = "com_github_cncf_udpa",
     )

bazel/repository_locations.bzl

@@ -28,6 +28,17 @@ REPOSITORY_LOCATIONS_SPEC = dict(
             "org_golang_x_text",
         ],
     ),
+    com_github_bazelbuild_buildtools = dict(
+        project_name = "Bazel build tools",
+        project_desc = "Developer tools for working with Google's bazel buildtool.",
+        project_url = "https://github.com/bazelbuild/buildtools",
+        version = "4.0.0",
+        sha256 = "0d3ca4ed434958dda241fb129f77bd5ef0ce246250feed2d5a5470c6f29a77fa",
+        strip_prefix = "buildtools-4.0.0",
+        urls = ["https://github.com/bazelbuild/buildtools/archive/4.0.0.tar.gz"],
+        release_date = "2021-02-03",
+        use_category = ["api"],
+    ),
     com_github_cncf_udpa = dict(
         project_name = "xDS API",
         project_desc = "xDS API Working Group (xDS-WG)",