nix: add black and isort to the closure (#2619)

To make sure that everything is formatted with the same black version
as CI.

I sometimes use isort for new files to get nicely ordered imports,
so add it as well. Also set the isort configuration to format in a
way that is compatible with black.

clients/python/pyproject.toml

@@ -27,3 +27,6 @@ asyncio_mode = "auto"
 [build-system]
 requires = ["poetry-core>=1.0.0"]
 build-backend = "poetry.core.masonry.api"
+
+[tool.isort]
+profile = "black"

integration-tests/pyproject.toml

@@ -13,3 +13,6 @@ pytest = "^7.4.0"
 pytest-asyncio = "^0.21.1"
 docker = "^7"
 numpy = "^1.20"
+
+[tool.isort]
+profile = "black"

nix/impure-shell.nix

 {
   mkShell,
+  black,
+  isort,
   openssl,
   pkg-config,
   protobuf,
@@ -14,6 +16,8 @@
 mkShell {
   buildInputs =
     [
+      black
+      isort
       openssl.dev
       pkg-config
       (rust-bin.stable.latest.default.override {

server/pyproject.toml

@@ -82,3 +82,6 @@ requires = [
     "poetry-core>=1.0.0",
 ]
 build-backend = "poetry.core.masonry.api"
+
+[tool.isort]
+profile = "black"