[MacPorts] #57736: Allow the location of archive_sites.conf and pubkeys.conf to be configured in macports.conf

[MacPorts]

#57736: Allow the location of archive_sites.conf and pubkeys.conf to be configured
in macports.conf
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Reporter: ryandesign | Owner: (none)
Type: enhancement | Status: new
Priority: Normal | Milestone:
Component: base | Version: 2.5.4
Keywords: | Port:
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In macports.conf, the location of the sources.conf file can be configured
using the `sources_conf` key. Similarly, the location of the variants.conf
file can be configured using the `variants_conf` key. Combined with
setting the environment variable `PORTSRC` to the path of an alternate
macports.conf, this allows completely separate settings to be used for a
particular invocation of the MacPorts command. mpbb uses this.

Why can't the locations of the archive_sites.conf and pubkeys.conf files
be configured in the same way?