Add support for PyYAML v6

Author: newAM

CHANGELOG-python.md

@@ -5,6 +5,8 @@ This changelog tracks the Python `svdtools` project. See
 
 ## [Unreleased]
 
+* Add support for PyYAML v6
+
 ## [v0.1.21] 2022-01-15
 
 * Provide option to opt out of regex replace of 0's in description when

pyproject.toml

@@ -14,7 +14,7 @@ requires-python = ">=3.6"
 description-file = "README.md"
 requires = [
   "click ~= 8.0",
-  "PyYAML ~= 5.3",
+  "PyYAML >= 5.3, < 7",
   "lxml ~= 4.6",
   "braceexpand ~= 0.1.7",
 ]