build: add melange config for libpst

[MthwRobinson]

Summary

Adds the melange config to build libpst for wolfi-base. The pipeline builds the CLI package, but not the Python bindings and the build pipeline does not include the man pages. Build has only been tested on x86_64.

Test instructions

To build the packages, run:

docker run --privileged --rm \
    -v "${PWD}":/work \
    cgr.dev/chainguard/melange \
    build libpst.yaml \
    --arch=x86_64 \
    --signing-key melange.rsa

After the package is built, install it in wolfi-base with:

apk add --allow-untrusted libpst-0.6.76-r0.apk

Once it's installed, verify that readpst is available by runnign readpst --help.

[jonathandine]

just a general question do we need to have the copyright done and set for the package and already here for the library/when do we need to that? Or will it be covered by the general copyright of core-product?

[tabossert]

Becoming Melange ninja's

[MthwRobinson]

🥷 <(Let's Melange!)