deps: switch back to released mf2py

requirements.txt

@@ -5,7 +5,6 @@ git+https://github.com/dvska/gdata-python3.git#egg=gdata
 git+https://github.com/snarfed/granary.git#egg=granary
 git+https://github.com/snarfed/httpsig.git@HTTPSignatureAuth-sign-header#egg=httpsig
 git+https://github.com/snarfed/lexrpc.git#egg=lexrpc
-git+https://github.com/snarfed/mf2py.git@metaformats#egg=mf2py
 git+https://github.com/snarfed/mox3.git#egg=mox3
 git+https://github.com/snarfed/negotiator.git@py3#egg=negotiator
 git+https://github.com/snarfed/oauth-dropins.git#egg=oauth_dropins
@@ -63,6 +62,7 @@ Jinja2==3.1.2
 jsonschema==4.20.0
 lxml==4.9.3
 MarkupSafe==2.1.3
+mf2py==1.1.3
 mf2util==0.5.2
 multiformats==0.2.1
 multiformats-config==0.2.0.post4