Remove Icecast (Unmaintained since 13 March 2022)

[Ki-er]

As part of #1
No commits since March 2022

[nodiscc]

No commits since March 2022

There are, but on the devel branch https://gitlab.xiph.org/xiph/icecast-server/-/branches

Also icecast is extremely mature software and might not need frequent maintenance anymore (https://tracker.debian.org/pkg/icecast2 shows that it has been available in Debian stable since 2007). This is one of the few pieces of software that I'm running, which I sometimes forget entirely, since it's so damn reliable.

I suggest closing this and/or adding it to last_updated_skip in https://github.com/awesome-selfhosted/awesome-selfhosted-data/tree/master/.hecat

[kokomo123]

As nodiscc suggested, I shall agree with his statements. Feel free to change this PR to last_updated_skip, but I can go ahead in closing this PR if everyone's in agreement.

[Ki-er]

As its a GitLab project and not in the list yet, ill close this for now.