sccache 0.16.0

Sccache is a ccache-like tool. It is used as a compiler wrapper and avoids compilation when possible. Sccache has the capability to utilize caching in remote storage environments, including various cloud storage options, or alternatively, in local storage.
Documentation
# WebDAV

Users can configure sccache to cache incremental build artifacts in a remote WebDAV service.
The following services all expose a WebDAV interface and can be used as a backend:

- [Ccache HTTP storage backend]https://ccache.dev/manual/4.7.4.html#_http_storage_backend
- [Bazel Remote Caching]https://bazel.build/remote/caching.
- [Gradle Build Cache]https://docs.gradle.org/current/userguide/build_cache.html

Set `SCCACHE_WEBDAV_ENDPOINT` to an appropriate webdav service endpoint to enable remote caching.
Set `SCCACHE_WEBDAV_KEY_PREFIX` to specify the key prefix of cache.

The `SCCACHE_WEBDAV_RW_MODE` environment variable can be set to `READ_ONLY` to make sccache use this backend in read-only mode. The default is `READ_WRITE`.

## Credentials

Sccache is able to load credentials from the following sources:

- Set `SCCACHE_WEBDAV_USERNAME`/`SCCACHE_WEBDAV_PASSWORD` to specify the username/password pair for basic authentication.
- Set `SCCACHE_WEBDAV_TOKEN` to specify the token value for bearer token authentication.