[Bug]: Logging for missing packages should only show unique set

[cicdguy]

What happened?

The output regarding missing packages should show a unique set.

Relevant log output

Instead of seeing:

Could not find package huxtable (version >= 2.0.0) in any of the repositories.
Could not find package r2rtf (version >= 0.3.2) in any of the repositories.
Could not find package flextable (version >= 0.8.4) in any of the repositories.
Could not find package officer (version >= 0.5.0) in any of the repositories.
Could not find package r2rtf (version >= 0.3.2) in any of the repositories.
Could not find package vdiffr (version >= 1.0.0) in any of the repositories.
Could not find package vdiffr in any of the repositories.

I want to see:

Could not find package huxtable (version >= 2.0.0) in any of the repositories.
Could not find package r2rtf (version >= 0.3.2) in any of the repositories.
Could not find package flextable (version >= 0.8.4) in any of the repositories.
Could not find package officer (version >= 0.5.0) in any of the repositories.
Could not find package vdiffr in any of the repositories.

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