chore(ci-governance): add .gitattributes to fix Linguist misdetection

Repo Linter's python-package-metadata-exists rule fires because Linguist
classifies the repo as containing a Python package due to a single helper
script (hack/tilt/scripts/prepare_values.py) used only by local Tilt dev
tooling, not a real Python package. Marking it linguist-detectable=false
removes the false-positive language classification without touching the
script itself.

Signed-off-by: Ivan Alvarez Sabin <ivanasabi@ext.inditex.com>

Author: ivanasabi

.gitattributes

@@ -0,0 +1 @@
+hack/tilt/scripts/prepare_values.py linguist-detectable=false