community/suitesparse: force installation of headers into usr/include

Seems like the builders act differently than CI and try to install headers
into /usr/local/include. [1]

Relevant log snippet:

```
make[3]: Leaving directory '/home/buildozer/aports/community/suitesparse/src/SuiteSparse-5.6.0/GraphBLAS/build'
Install the project...
-- Install configuration: "Release"
-- Installing: /home/buildozer/aports/community/suitesparse/pkg/suitesparse/usr/lib/libgraphblas.so.3.1.1
-- Installing: /home/buildozer/aports/community/suitesparse/pkg/suitesparse/usr/lib/libgraphblas.so.3
-- Installing: /home/buildozer/aports/community/suitesparse/pkg/suitesparse/usr/lib/libgraphblas.so
CMake Error at cmake_install.cmake:107 (file):
  file cannot create directory: /usr/local/include.  Maybe need
  administrative privileges.
```

Note that this did not happen on CI in !15718 [2][3]

[1] https://build.alpinelinux.org/buildlogs/build-edge-x86_64/community/suitesparse/suitesparse-5.6.0-r2.log
[2] https://gitlab.alpinelinux.org/Leo/aports/-/pipelines/63917
[3] https://gitlab.alpinelinux.org/Leo/aports/-/pipelines/63916
7 jobs for !16016 with suitesparse in 1 minute and 11 seconds (queued for 1 second)
merge request