refactor: Update Makefile to use dynamic shell path (#10801)

Update the `Makefile` to use the dynamic shell path instead of the
hardcoded `/bin/bash`. This ensures that the correct shell is used
across different environments. Additionally, the environment variable
`SHELL` is updated to use the `which` command to locate the path of the
bash shell.

Makefile

@@ -6,7 +6,7 @@ endif
 
 
 # use bash everywhere !
-SHELL := /bin/bash
+SHELL := $(shell which bash)
 # some vars
 ENV_FILE ?= .env
 NAME = "ProductOpener"