Use 10 character short hash for version string of git packages

[sp4ghet]

Tested using Unity 2021.2.0f1 as well as 2022.2.1f1.

For example, when using this package with the following manifest.json:

"dependencies": {
    "com.hecomi.hlsltoolsforvisualstudioconfiggenerator": "https://github.com/hecomi/HLSLToolsForVisualStudioConfigGenerator.git#upm",
...

The Library/PackageCache directory has the following directory for the local cache of the repository/package:

Library\PackageCache\com.hecomi.hlsltoolsforvisualstudioconfiggenerator@24c1c38f35

The packages-lock.json entry looks like this:

"dependencies": {
    "com.hecomi.hlsltoolsforvisualstudioconfiggenerator": {
      "version": "https://github.com/hecomi/HLSLToolsForVisualStudioConfigGenerator.git#upm",
      "depth": 0,
      "source": "git",
      "dependencies": {},
      "hash": "24c1c38f35bd3111c1b7962ef92870bf5748f875"
    },
...

I'm not sure how stable this behavior is in terms of backward compatibility or when the behavior changed (I assume you tested git packages on an older version of unity), but it seems the newer versions of unity use this method of caching.

[hecomi]

I created a new project locally on my Mac using Unity 2021.3.16f1 and 2022.2.6f1 (Apple Silicon) and found that the path is still based on the version rather than the hash. I would like to investigate under what conditions the hash path is used.

Please let me know if you discover anything regarding this matter.

[sp4ghet]

Hi, I am running Windows 10.
Please let me know if there is some other platform info you would like.

[hecomi]

Ah, sorry! This is the case when you add the package from "Add packages from git URL...". I could reproduce it.