(#3591) Remove no7zip build tasks

[gep13]

Description Of Changes

This commit removes the no longer required no7zip build tasks, and also the associated sln and csproj entries, from the support branch.

This work has already been completed on the develop branch via this PR.

Motivation and Context

Previously, it was necessary to build a version of choco.exe that didn't include the 7zip binaries, however, this version of Chocolatey CLI is no longer required.

To simplify the overall build process, and also the release steps required, the decision was taken to completely remove the no7zip build.

Testing

• Full local build completed using .\build.bat.
• Verify no no7zip artifacts are created
• Verify that normal artifacts from build are created, i.e. chocolatey, chocolatey.lib, chocolatey.powershell nupkg's
• CI builds will be completed as a result of this PR.

Operating Systems Testing

N/A

Change Types Made

• Bug fix (non-breaking change).
• Feature / Enhancement (non-breaking change).
• Breaking change (fix or feature that could cause existing functionality to change).
• Documentation changes.
• PowerShell code changes.
• Build changes

Change Checklist

• Requires a change to the documentation.
• Documentation has been updated.
• Tests to cover my changes, have been added.
• All new and existing tests passed?
• PowerShell code changes: PowerShell v3 compatibility checked?

Related Issue

Fixes #3591

[AdmiringWorm]

LGTM