Release documentation folder names do not strip tag prefix

[JonatanAntoni]

Issue description

Given release tags are using "complex" prefix (e.g., pack/v<VERSION>), like in CMSIS-View.

On release, the documentation is pushed onto the gh-pages branch into a folder named like the tag. For plain tags (without / in the name) this results in a new top-level folder as expected. But for "complex" tag names (with / in the name) this creates a folder hierarchy.

For CMSIS-View for example, having the release tags pack/v1.0.0 and pack/v1.1.0 lead to the folder structure on gh-pages branch like this:

 📦
 ┣ 📂 pack 
 ┃ ┣ 📂 v1.0.0                 release 1.0.0 documentation
 ┃ ┗ 📂 v1.1.0                 release 1.1.0 documentation
 ┣ 📂 main                     main branch documentation
 ┣ 📂 latest -> pack/v1.1.0    link to latest release documentation
 ┗ 📋 versions.js              Version selector

Unfortunately, when updating the versions.js file, searching for documentation versions is limited to the first directory level. This leads to documentation version published into some subfolder hierarchy not to be listed.

Expected behaviour

Instead, on the gh-pages branch all release versions should show up as s top-level folder named according to the release version. The release version is considered to be the tag name without the prefix.

For above example, the expected folder structure is like this:

 📦
 ┣ 📂 1.0.0                  release 1.0.0 documentation
 ┣ 📂 1.1.0                  release 1.1.0 documentation
 ┣ 📂 main                   main branch documentation
 ┣ 📂 latest -> 1.1.0        link to latest release documentation
 ┗ 📋 versions.js            Version selector

[JonatanAntoni]

The problem is in the GitHub action:
https://github.com/Open-CMSIS-Pack/gen-pack-action/blob/a5a6a9c0544430092f2f47305d90b8b484aaf1ed/action.yml#L206