[components] Fix uv error messages/warnings in dagster-dg tests (#2…

…6443)

## Summary & Motivation

- `uv sync` was being incorrectly invoked using `uv run`
- Now all `uv` commands are run in an environment with `VIRTUAL_ENV`
unset, to get rid of the warnings about the uv-resolved environment not
matching the shell `VIRTUAL_ENV`

## How I Tested These Changes

Observed test output.

python_modules/libraries/dagster-dg/dagster_dg/generate.py

@@ -1,4 +1,5 @@
 import os
+import subprocess
 import textwrap
 from pathlib import Path
 from typing import Optional, Tuple
@@ -11,6 +12,8 @@
     discover_git_root,
     execute_code_location_command,
     generate_subtree,
+    get_uv_command_env,
+    pushd,
 )
 
 
@@ -63,7 +66,8 @@ def generate_code_location(path: Path, editable_dagster_root: Optional[str] = No
     )
 
     # Build the venv
-    execute_code_location_command(Path(path), ("uv", "sync"))
+    with pushd(path):
+        subprocess.run(["uv", "sync"], check=True, env=get_uv_command_env())
 
 
 def generate_component_type(context: CodeLocationDirectoryContext, name: str) -> None:

python_modules/libraries/dagster-dg/dagster_dg/utils.py

@@ -4,7 +4,7 @@
 import re
 import subprocess
 from pathlib import Path
-from typing import Any, Final, Iterator, List, Optional, Sequence, Union
+from typing import Any, Final, Iterator, List, Mapping, Optional, Sequence, Union
 
 import click
 import jinja2
@@ -17,10 +17,19 @@
 def execute_code_location_command(path: Path, cmd: Sequence[str]) -> str:
     with pushd(path):
         full_cmd = [*_CODE_LOCATION_COMMAND_PREFIX, *cmd]
-        result = subprocess.run(full_cmd, stdout=subprocess.PIPE, check=False)
+        result = subprocess.run(
+            full_cmd, stdout=subprocess.PIPE, env=get_uv_command_env(), check=True
+        )
         return result.stdout.decode("utf-8")
 
 
+# uv commands should be executed in an environment with no pre-existing VIRTUAL_ENV set. If this
+# variable is set (common during development) and does not match the venv resolved by uv, it prints
+# undesireable warnings.
+def get_uv_command_env() -> Mapping[str, str]:
+    return {k: v for k, v in os.environ.items() if not k == "VIRTUAL_ENV"}
+
+
 def discover_git_root(path: Path) -> Path:
     while path != path.parent:
         if (path / ".git").exists():