What does that matter? You’re using Vulkan; the only version that matters to you is the one defined by the extension KHR_vulkan_glsl. You’re not going to be able to write a viable GLSL shader that can compile to Vulkan without at least GLSL version 4.20 (which permits the use of binding in interface blocks and opaque uniforms).
So just set the version to 4.60 and move on.
But, as a matter of interest, there are 13 extant versions of GLSL (not counting the 4 OpenGL ES versions). This doesn’t include 1.00, as this is not exposed by any core version of OpenGL; it only exists as an extension.
What is std140 ?
This is one of the standard layouts that you can apply to buffer-backed interface blocks. These define the byte offset and alignment of every scalar type stored in such a block.