Change mth5 repository branch from 'main' to 'master'

Author: kujaku11

requirements.txt

@@ -1,6 +1,6 @@
 # Install GitHub versions first to ensure compatibility with Python 3.11+
 git+https://github.com/kujaku11/mt_metadata.git@main
-git+https://github.com/kujaku11/mth5.git@main
+git+https://github.com/kujaku11/mth5.git@master
 git+https://github.com/simpeg/aurora@patches
 git+https://github.com/MTgeophysics/mtpy-v2.git@main
 git+https://github.com/kujaku11/mth5_test_data.git