add .env for a straightforward dev deployment (#354)

## Description

In the process of setting up the dev environment, an empty .env file is
requested to build the image. Since there is no visible impact on having
it not having it, for consistency it is better to remove this not used
dependency from the docker compose yml file.

## Related Issue(s)

somehow related to #342 

## Breaking Change?

No major changes are going to happen

## Checklist

- [ ] I have made corresponding changes to the documentation (if
required)
- [ ] I have added tests that prove my fix is effective or that my
feature works

---------

Co-authored-by: giovanni.corsetti <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Harel Shein <[email protected]>

.gitignore

@@ -108,7 +108,6 @@ celerybeat.pid
 *.sage.py
 
 # Environments
-.env
 .venv
 env/
 venv/

.pre-commit-config.yaml

@@ -1,6 +1,14 @@
 # See https://pre-commit.com for more information
 # See https://pre-commit.com/hooks.html for more hooks
 repos:
+  - repo: local
+    hooks:
+      - id: check-env-file
+        name: Check if .env file is empty
+        entry: bash -c 'FILE=dev/.env; if [ -s "$FILE" ]; then echo "$FILE is not empty. Please remove its content."; exit 1; fi'
+        language: system
+        types: [file]
+        pass_filenames: false
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.4.0
     hooks: