fix win-64 tensorflow dependency

[spreka]

A separate tensorflow dependency is added for win-64 to fix package not found error when installing with conda on Windows.

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipe) and found some lint.

Here's what I've got...

For recipe:

• Selectors are suggested to take a <two spaces>#<one space>[<expression>] form. See lines [29, 30]
• noarch packages can't have selectors. If the selectors are necessary, please remove noarch: python.

[goanpeca]

We need to remove this line. (noarch: python)

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipe) and found some lint.

Here's what I've got...

For recipe:

• Non noarch packages should have python requirement without any version constraints.
• Non noarch packages should have python requirement without any version constraints.

[goanpeca]

There are ongoing efforts conda-forge/tensorflow-feedstock#111 to have tensorflow builds for windows. But until that happens, the bundle app for napari will not be able to provide plugins for the windows platform that rely on tensorflow.