new icon: msbuild (original, plain, line)

[MattKotsenas]

Double check these details before you open a PR

• PR does not match another non-stale PR currently opened
• PR name matches the format new icon: Icon name (versions separated by comma). More details here
• PR's base is the develop branch.
• Your icons are inside a folder as seen here
• SVG matches the standards laid out here
• A new object is added in the devicon.json file at the correct alphabetic position as seen here

This PR closes NONE

Link to prove your SVG is correct and up-to-date.

https://github.com/dotnet/msbuild/tree/main/branding