Authorises access to a private GitHub NuGet package source, so you can restore packages.

• This Action writes the PAT value to disk in plain text... because NuGet requires that on linux.
• Please ensure that you scope the PAT to only read packages and that you are prepared to accept the risk of the PAT escaping.

      - name: Authorise NuGet
        uses: StirlingLabs/GithubNugetAuthAction@main
        with:
          owner: ${{github.repository_owner}}
          name: MyNuPkgRepo
          token: ${{secrets.NUGET_PAT}}
      - name: Restore NuPkg
        run: dotnet restore SolutionName.sln