Bump the minimum required channels version to v1.4.0

This is to be able to use type guards in with `Receiver.filter` to
narrow the received type and the new `WithPrevious` class.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

pyproject.toml

@@ -30,7 +30,7 @@ dependencies = [
   # changing the version
   # (plugins.mkdocstrings.handlers.python.import)
   "frequenz-client-microgrid >= 0.6.0, < 0.7.0",
-  "frequenz-channels >= 1.2.0, < 2.0.0",
+  "frequenz-channels >= 1.4.0, < 2.0.0",
   "frequenz-quantities >= 1.0.0rc3, < 2.0.0",
   "networkx >= 2.8, < 4",
   "numpy >= 1.26.4, < 2",