Relax paho-mqtt dependency to >=1.5.0 for Yocto compatibility

Matches ebus-mqtt-client 0.1.2 which relaxed the same constraint.
Bump ebus-mqtt-client floor to >=0.1.2 and version to 0.1.5.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dcj

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "ebus-sdk"
-version = "0.1.4"
+version = "0.1.5"
 description = "Python SDK for Homie MQTT Convention (eBus)"
 readme = "README.md"
 requires-python = ">=3.10"
@@ -25,8 +25,8 @@ classifiers = [
     "Topic :: Internet :: WWW/HTTP",
 ]
 dependencies = [
-    "ebus-mqtt-client>=0.1.0",
-    "paho-mqtt>=2.0.0",
+    "ebus-mqtt-client>=0.1.2",
+    "paho-mqtt>=1.5.0",
 ]
 
 [project.optional-dependencies]