ToolsVersion should be ignored by MSBuild task

MSBuild ignores ToolsVersion in most places but the MSBuild task is still trying to honor it

### Steps to reproduce

If you specify an invalid ToolsVersion to an MSBuild task invocation, the build will fail:

Project file
```xml

```
Command line
```
msbuild /bl
```
### Expected behavior
ToolsVersion to not be respected and ignored like ToolsVersion is ignored everywhere else.

### Actual behavior
Build error:
```
error MSB4132: The tools version "BadToolsVersion" is unrecognized. Available tools versions are "Current", "2.0", "3.5", "4.0".
```

### Environment data
`msbuild /version` output:
```
Microsoft (R) Build Engine version 16.1.59-preview+gd8f1537cf1 for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.

16.1.59.61912
```