fix: Pin newer upstream Aptly action

[jinnatar]

Bugfix for kanidm_ppa.list having the wrong key type, Fixes #6

This is a more targeted fix than #5 which turned out to be more complex.

[jinnatar]

File produced:

%> unzip -p kanidm_ppa_snapshot.zip kanidm_ppa.list
# You probably want to use only one of the examples below!
# Example for enabling only the stable component on noble: 
deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/kanidm_ppa.asc] https://kanidm.github.io/kanidm_ppa noble stable
# Example for enabling only the stable component on jammy: 
deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/kanidm_ppa.asc] https://kanidm.github.io/kanidm_ppa jammy stable
# Example for enabling only the nightly component on noble: 
deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/kanidm_ppa.asc] https://kanidm.github.io/kanidm_ppa noble nightly
# Example for enabling only the stable component on bookworm: 
deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/kanidm_ppa.asc] https://kanidm.github.io/kanidm_ppa bookworm stable
# Example for enabling only the nightly component on bookworm: 
deb [arch=amd64,arm64 signed-by=/etc/apt/trusted.gpg.d/kanidm_ppa.asc] https://kanidm.github.io/kanidm_ppa bookworm nightly

.. So looking good!