Change the way uv is installed

[nicolargo]

Replace:

install-uv: ## Instructions to install the UV tool
	@echo "Install the UV tool (https://astral.sh/uv/)"
	@echo "Please install the UV tool manually"
	@echo "For example with: curl -LsSf https://astral.sh/uv/install.sh | sh"
	@echo "Or via a package manager of your distribution"
	@echo "For example for Snap: snap install astral-uv"

upgrade-uv: ## Upgrade the UV tool
	uv self update

by

uv:
	python3 -m venv .venv-uv
	.venv-uv/bin/pip install uv

uv-upgrade:
	.venv-uv/bin/pip install --upgrade pip
	.venv-uv/bin/pip install --upgrade uv

and change the rest of the Makefile to use uv inside .venv-uv/bin/uv

[nicolargo]

Merged into develop.