Cannot use PDK and Bolt in the same PowerShell session (Process)

If you run PDK, then Bolt and then PDK again, PDK will terminate with a ruby error

C:\Source> pdk --version

1.14.1

C:\Source> bolt --version

1.31.1

C:\Source> pdk --version

Traceback (most recent call last):

C:\PROGRA~1\PUPPET~1\Bolt\bin\ruby: No such file or directory -- C:/PROGRA~1/PUPPET~1/Bolt/bin/pdk (LoadError)

This also occurs in the reverse (bolt -> PDK -> Bolt)

C:\Source> bolt --version

1.31.1

C:\Source> pdk --version

1.14.1

C:\Source> bolt --version

C:\PROGRA~1\PUPPET~1\DEVELO~1\private\ruby\2.4.9\bin\ruby.exe: No such file or directory -- C:/PROGRA~1/PUPPET~1/DEVELO~1/private/ruby/2.4.9/bin/bolt (LoadError)

This is due to both PowerShell wrappers managing the same Environment Variables (RUBY_DIR, SSL_CERT_FILE and SSL_CERT_DIR)

https://github.com/puppetlabs/pdk-vanagon/blob/021c4382233a04a8e0a1536352fb9f27a300bf80/resources/files/windows/PuppetDevelopmentKit/PuppetDevelopmentKit.psm1#L6-L8

https://github.com/puppetlabs/bolt-vanagon/blob/c48d7c60b7ec51675eeb11d64e8bc6c802883f2e/resources/files/windows/PuppetBolt/PuppetBolt.psm1#L6-L9

Because these environment variables are only set at module import time, not at function invocation time, both wrappers are stomping over each other and causing errors.

Ideally environment variables should not be used at all and instead use command line invocations.