Fix requirements-dev headers to reflect uv pip compile tooling

Update requirements-dev.txt header from pip-compile/Python 3.9 to
match the uv pip compile format used elsewhere in the repo. Also
clarify the regenerate command comment in requirements-dev.in.

Fixes review feedback on PR #106.

Author: mrbiggred

requirements-dev.in

@@ -1,4 +1,4 @@
 # Dev-only dependencies (not needed for production builds)
-# uv pip compile requirements-dev.in --output-file requirements-dev.txt
+# Regenerate with: uv pip compile requirements-dev.in --output-file requirements-dev.txt
 
 Pillow>=10.0.0

requirements-dev.txt

@@ -1,8 +1,4 @@
-#
-# This file is autogenerated by pip-compile with Python 3.9
-# by the following command:
-#
-#    pip-compile --output-file=requirements-dev.txt requirements-dev.in
-#
+# This file was autogenerated by uv via the following command:
+#    uv pip compile requirements-dev.in --output-file requirements-dev.txt
 pillow==11.3.0
     # via -r requirements-dev.in