[ccache] Ccache version 4.5 has been released

[Joel Rosdahl]

Ccache version 4.5 is now available. Release archives can be found here:

    https://ccache.dev/download.html

New features:

  - Made various improvements to the cache entry format. Among other things,
    the header now contains a creation timestamp and a note of the ccache
    version used to create the entry. The cache entry checksum has also been
    upgraded to use 128-bit XXH3 instead 64-bit XXH3.

  - Added support for cache namespaces. If a namespace configured, e.g. using
    “CCACHE_NAMESPACE=some_string”, the namespace string will be added to the
    hashed data for each compilation. This will make the associated cache
    entries logically separate from cache entries in other namespaces, but they
    will still share the same storage space. Cache entries can also be
    selectively removed from the primary cache with the new command line option
    “--evict-namespace”, potentially in combination with “--evict-older-than”.

  - Made HTTP keep-alive configurable, defaulting to off for now.

  - Added support for rewriting absolute path to Clang option
    “--gcc-toolchain”.

Compatibility notes:

  - A consequence of the changed cache entry format is that ccache 4.5 will not
    share cache entries with earlier versions. Different ccache versions can
    however still use the same cache storage without any issues.

Bug fixes:

  - Fixed a problem with special characters in the user info part of URLs for
    HTTP storage.

  - Fixed win32 log messages about file locks.

  - Fixed debug directory handling on Windows.

  - The hard link and file clone features are now disabled when secondary
    storage is used since they only work for the local primary cache.

Contributors (in alphabetical order) to this release:

  - Alexander Falkenstern
  - Gregor Jasny
  - Joel Rosdahl
  - Luboš Luňák
  - Russell McClellan

Thanks!

-- Joel