Use "ENV key=value" instead of "ENV key value" in Dockerfiles

The old syntax for ENV and LABEL is marked as deprecated in docker buildx v0.14.0

https://docs.docker.com/reference/build-checks/legacy-key-value-format/
https://github.com/moby/buildkit/pull/4923

{{cookiecutter.project_slug}}/compose/local/django/Dockerfile

@@ -27,9 +27,9 @@ FROM python AS python-run-stage
 ARG BUILD_ENVIRONMENT=local
 ARG APP_HOME=/app
 
-ENV PYTHONUNBUFFERED 1
-ENV PYTHONDONTWRITEBYTECODE 1
-ENV BUILD_ENV ${BUILD_ENVIRONMENT}
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV BUILD_ENV=${BUILD_ENVIRONMENT}
 
 WORKDIR ${APP_HOME}
 

{{cookiecutter.project_slug}}/compose/local/docs/Dockerfile

@@ -5,7 +5,7 @@ FROM docker.io/python:3.12.4-slim-bookworm AS python
 # Python build stage
 FROM python AS python-build-stage
 
-ENV PYTHONDONTWRITEBYTECODE 1
+ENV PYTHONDONTWRITEBYTECODE=1
 
 RUN apt-get update && apt-get install --no-install-recommends -y \
   # dependencies for building Python packages
@@ -29,8 +29,8 @@ RUN pip wheel --no-cache-dir --wheel-dir /usr/src/app/wheels  \
 FROM python AS python-run-stage
 
 ARG BUILD_ENVIRONMENT
-ENV PYTHONUNBUFFERED 1
-ENV PYTHONDONTWRITEBYTECODE 1
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
 
 RUN apt-get update && apt-get install --no-install-recommends -y \
   # To run the Makefile

{{cookiecutter.project_slug}}/compose/local/node/Dockerfile

@@ -6,4 +6,4 @@ COPY ./package.json /app
 
 RUN npm install && npm cache clean --force
 
-ENV PATH ./node_modules/.bin/:$PATH
+ENV PATH=./node_modules/.bin/:$PATH

{{cookiecutter.project_slug}}/compose/production/django/Dockerfile

@@ -53,9 +53,9 @@ FROM python AS python-run-stage
 ARG BUILD_ENVIRONMENT=production
 ARG APP_HOME=/app
 
-ENV PYTHONUNBUFFERED 1
-ENV PYTHONDONTWRITEBYTECODE 1
-ENV BUILD_ENV ${BUILD_ENVIRONMENT}
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV BUILD_ENV=${BUILD_ENVIRONMENT}
 
 WORKDIR ${APP_HOME}