Expired certificate in verification signature

[RBotfield]

The signature on the latest release is signed using an expired certificate.

Verification

$ gpg2 --verify dephpend-0.8.0.phar.asc dephpend-0.8.0.phar

gpg: Signature made Sun May  2 14:09:30 2021 BST
gpg:                using RSA key 44CC65DC01D2FC05AD6F3DBD76835C9464877BDD
gpg:                issuer "[email protected]"
gpg: Can't check signature: No public key

Checking the cert provided on OpenPGP

$ curl -s "https://keys.openpgp.org/pks/lookup?op=get&options=mr&search=44CC65DC01D2FC05AD6F3DBD76835C9464877BDD" | gpg2

gpg: WARNING: no command supplied.  Trying to guess what you mean ...
pub   rsa4096 2019-07-14 [SC] [expired: 2020-07-13]
      44CC65DC01D2FC05AD6F3DBD76835C9464877BDD
uid           Michael Haeuslmann <[email protected]>
sub   rsa4096 2019-07-14 [E] [expired: 2020-07-13]

Also shows as an issue installing with Phive

$ phive install dephpend

Phive 0.15.0 - Copyright (C) 2015-2021 by Arne Blankerts, Sebastian Heuer and Contributors
Downloading https://api.github.com/repos/mihaeu/dephpend/releases
Downloading https://github.com/mihaeu/dephpend/releases/download/0.8.0/dephpend-0.8.0.phar
Downloading https://github.com/mihaeu/dephpend/releases/download/0.8.0/dephpend-0.8.0.phar.asc
[ERROR]    Signature could not be verified 
[ERROR]    unknown error code 

Checking the key pulled by phive

$ gpg2 --list-keys --no-default-keyring --keyring ${HOME}/.phive/gpg/pubring.kbx | grep "44CC65DC01D2FC05AD6F3DBD76835C9464877BDD" -C2

pub   rsa4096 2019-07-14 [SC] [expired: 2020-07-13]
      44CC65DC01D2FC05AD6F3DBD76835C9464877BDD
uid           [ expired] Michael Haeuslmann <[email protected]>