Import Debian changes 241-7~deb10u3

systemd (241-7~deb10u3) buster; urgency=medium

  * core: set fs.file-max sysctl to LONG_MAX rather than ULONG_MAX.
    Since kernel 5.2 (but also stable kernels like 4.19.53) the kernel
    thankfully returns proper errors when we write a value out of range to
    the sysctl. Which however breaks writing ULONG_MAX to request the
    maximum value. Hence let's write the new maximum value instead,
    LONG_MAX. (Closes: #945018)
  * core: change ownership/mode of the execution directories also for static
    users.
    This ensures that execution directories like CacheDirectory and
    StateDirectory are properly chowned to the user specified in User= before
    launching the service. (Closes: #919231)