Install poetry dependencies with --no-root (go-gitea#27919) (go-gitea#27920)

Backport go-gitea#27919 by @silverwind

Poetry 1.7.0 or higher will print a warning otherwise, see discussions:

python-poetry/poetry#8369
python-poetry/poetry#1132

> --no-root Do not install the root package (the current project).

Co-authored-by: silverwind <[email protected]>

Author: GiteaBot

Makefile

@@ -922,7 +922,7 @@ node_modules: package-lock.json
 	@touch node_modules
 
 .venv: poetry.lock
-	poetry install
+	poetry install --no-root
 	@touch .venv
 
 .PHONY: update