No pkg-config .pc file installed.

I expected a pkg-config .pc file to get installed, but no such file is installed:

```
$ meson install
ninja: Entering directory `/usr/src/igsc/build'
ninja: no work to do.
Installing lib/libigsc.so.1.3.1 to /usr/local/lib/x86_64-linux-gnu
Installation failed due to insufficient permissions.
Attempt to use /usr/bin/sudo to gain elevated privileges? [y/n] y
[sudo: authenticate] Password:
Installing lib/libigsc.so.1.3.1 to /usr/local/lib/x86_64-linux-gnu
Installing lib/libigsc.a to /usr/local/lib/x86_64-linux-gnu
Installing src/igsc to /usr/local/bin
Installing /usr/src/igsc/build/igsc_lib.h to /usr/local/include
Installing symlink pointing to libigsc.so.1.3.1 to /usr/local/lib/x86_64-linux-gnu/libigsc.so.1
Installing symlink pointing to libigsc.so.1 to /usr/local/lib/x86_64-linux-gnu/libigsc.so
```

So when I try to build xpu-smi afterwards:
```
Run-time dependency igsc found: NO (tried pkgconfig and cmake)

meson.build:243:11: ERROR: Dependency "igsc" not found, tried pkgconfig and cmake
```

Inspect meson.build, especially the dependency setup around line 243, and reproduce the installation with `meson install`. Confirm that the installed library exposes the metadata xpu-smi expects through pkg-config; done means xpu-smi's Meson configure step reports that the igsc dependency is found.

Written by the indexing model from the issue text.