toktx transform does not work with current linux builds of ktx-software

[dbuck]

Describe the bug
I am unable to use gltf-transform etc1s on linux currently due to the semver restrictions.

ktx-software 4.0.0 linux builds are not returning valid semver strings from toktx --version

Related issue: KhronosGroup/KTX-Software#467

Output attempting to use the ktx-software-linux 4.0 build with gltf-transform 0.12.7

gltf# gltf-transform --version
0.12.7
gltf# gltf-transform etc1s ./staging/input.glb ./staging/output.glb

error: Unable to find "toktx" version. Confirm KTX-Software is installed.

gltf# toktx --version
toktx v4.0

To Reproduce
Steps to reproduce the behavior:
on linux, install ktx-software 4.0
attempt to use gltf-transform etc1s

Expected behavior
gltf-transform converts the embedded image data via toktx.

Versions:

• Version: v0.12.7
• Environment: Node.js
• ktx-software version: v4.0.0
• os: Ubuntu 18.04.5 LTS

Additional context
The solution may be 'Wait for an actual fix from KTX-Software build pipeline', but hopefully this issue can save someone else some amount of time if they also see this error.

[donmccurdy]

Hm, I guess as long as the toktx command exists, we could just log a warning if the version can't be parsed and then continue to try encoding? It may be a while before I can get to a non-CLI implementation.

[donmccurdy]

Merging into #358.