Remove deprecated argument from package call

Author: jimporter

CHANGES.md

@@ -1,5 +1,12 @@
 # Changes
 
+## v1.0.1 (in progress)
+
+### Bug fixes
+- Fix deprecation warning when configuring
+
+---
+
 ## v1.0.0 (2023-05-21)
 
 ### New features

build.bfg

@@ -12,7 +12,7 @@ install(includes)
 test_files = find_paths('test/**/*.cpp')
 
 try:
-    libmettle = package('mettle', headers=['mettle.hpp'])
+    libmettle = package('mettle')
     mettle = test_driver(['mettle', '--output=verbose'])
 
     for src in test_files: