docker_build: keep using cache when building with dev tools

odoo_scripts/docker_build.py

@@ -224,10 +224,10 @@
                 myfile.write("python-ipdb\n")
                 myfile.write(
                     "RUN pip install watchdog --disable-pip-version-check "
-                    "--system --no-cache-dir --only-binary wheel"
+                    "--system --only-binary wheel"
                 )
             elif odoo_type in (ODOO_7, ODOO_8):
                 myfile.write("python-ipdb\n")
                 myfile.write("RUN pip install pyinotify")
             else:
                 myfile.write(
@@ -228,11 +228,10 @@
                 )
             elif odoo_type in (ODOO_7, ODOO_8):
                 myfile.write("python-ipdb\n")
                 myfile.write("RUN pip install pyinotify")
             else:
                 myfile.write(
-                    "RUN python3 -m pip --no-cache-dir install pdbpp watchdog "
-                    "ipdb pyinotify\n"
+                    "RUN python3 -m pip install pdbpp watchdog ipdb pyinotify\n"
                 )
 
         dockerfile = debug_dockerfile