ci: move gen_gitlab_config to uv script (#15358)

## Description

This doesn't have to be defined as a riot venv, moving to a uv script
will make it easier to just do `scripts/gen_gitlab_config.py` and it'll
self-bootstrap a venv and what is needed.

## Testing

<!-- Describe your testing strategy or note what tests are included -->

## Risks

<!-- Note any risks associated with this change, or "None" if no risks
-->

## Additional Notes

<!-- Any other information that would be helpful for reviewers -->

Author: brettlangdon

.gitlab-ci.yml

@@ -54,7 +54,7 @@ tests-gen:
         # Use dd-octo-sts to get GitHub token
         export GH_TOKEN=$(dd-octo-sts token --scope DataDog/dd-trace-py --policy gitlab.github-access.read)
       fi
-    - riot -v run --pass-env -s gitlab-gen-config -v
+    - scripts/gen_gitlab_config.py --verbose
   needs: []
   artifacts:
     paths:

.riot/requirements/151a249.txt

@@ -151,15 +151,6 @@ def select_pys(min_version: str = MIN_PYTHON_VERSION, max_version: str = MAX_PYT
                 "standard-imghdr": latest,
             },
         ),
-        Venv(
-            name="gitlab-gen-config",
-            command="python scripts/gen_gitlab_config.py {cmdargs}",
-            pys=["3"],
-            pkgs={
-                "ruamel.yaml": latest,
-                "lxml": latest,
-            },
-        ),
         Venv(
             name="appsec",
             pys=select_pys(),

riotfile.py

@@ -1,9 +1,21 @@
-# This script is used to generate the GitLab dynamic config file in
-# .gitlab/tests.yml.
-#
-# To add new configuration manipulations that are based on top of the template
-# file in .gitlab/tests.yml, add a function named gen_<name> to this
-# file. The function will be called automatically when this script is run.
+#!/usr/bin/env scripts/uv-run-script
+# -*- mode: python -*-
+# /// script
+# requires-python = ">=3.9"
+# dependencies = [
+#     "riot>=0.20.1",
+#     "ruamel.yaml>=0.17.21",
+#     "lxml>=4.9.0",
+# ]
+# ///
+"""
+This script is used to generate the GitLab dynamic config file in
+.gitlab/tests.yml.
+
+To add new configuration manipulations that are based on top of the template
+file in .gitlab/tests.yml, add a function named gen_<name> to this
+file. The function will be called automatically when this script is run.
+"""
 
 from dataclasses import dataclass
 import datetime