https://invent.kde.org/frameworks/baloo/-/blob/048edc5d/src/file/kde-baloo.service.in#L9
expects the `kde-systemd-start-condition` executable to be in "baloo"s
installation directory, but unique nixpkgs derivations break this
assumption:
```
$ journalctl --user -u kde-baloo -o cat
Starting Baloo File Indexer Daemon...
kde-baloo.service: Failed to locate executable /nix/store/74g3ahh0k0x6d5rj5rxs1lxhzx81vgdd-baloo-5.95.0/bin/kde-systemd-start-condition: No such file or directory
kde-baloo.service: Failed at step EXEC spawning /nix/store/74g3ahh0k0x6d5rj5rxs1lxhzx81vgdd-baloo-5.95.0/bin/kde-systemd-start-condition: No such file or directory
kde-baloo.service: Skipped due to 'exec-condition'.
Condition check resulted in Baloo File Indexer Daemon being skipped.
```
```
$ systemctl --user cat kde-baloo | grep kde-systemd-start-condition
ExecCondition=/nix/store/74g3ahh0k0x6d5rj5rxs1lxhzx81vgdd-baloo-5.95.0/bin/kde-systemd-start-condition --condition "baloofilerc:Basic Settings:Indexing-Enabled:true"
```
`kde-systemd-start-condition` is provided by the "plasma-workspace"
derivation which depends on "baloo".
Replace the CMake macro with the generic current system's path to fix
service startup and to avoid a recursive dependency.
This patch adds an option enablePolkit to the kauth package, to allow
disabling polkit integration. The attr enablePolkit is understood by
one other package (tools/networking/connman); using the same name
allows to set it globally in ~/.config/nixpkgs/config.nix.
Fixes#99308.
Use an associative array to recognize paths that have already been seen by the
host path hook. This takes advantage of fast lookup of associative array keys in
Bash. The previous solution scanned a linear array, which was accidentally
quadratic.
