build: Indent cmake consistently

[HuidaeCho]

This PR applies consistent indentation to a cmake file.

[echoix]

Was this done manually or with a script? With a script, a tool, or linter, that could be run in pre-commit, it would prevent these kind of disreptencies to be created in the future.

The tool me and @nilason knows of isn't quite perfect (hard to configure to get something pleasant to read in all cases, and isn't creating potential merge conflicts easily) and we waited to have finished the initial implementation before formatting everything with a chosen style.

[m-kuhn]

FTR: for QField we use https://github.com/cheshirekow/cmake-format-precommit
it's not perfect but can be tuned by making additional commands available if someone is motivated https://github.com/opengisch/QField/blob/master/.cmake-format.yaml

https://github.com/opengisch/QField/blob/c7fbab2b1bb5e048389d9ca68aa83e7b7edaa759/.pre-commit-config.yaml#L56-L62

[echoix]

FTR: for QField we use https://github.com/cheshirekow/cmake-format-precommit

it's not perfect but can be tuned by making additional commands available if someone is motivated https://github.com/opengisch/QField/blob/master/.cmake-format.yaml

https://github.com/opengisch/QField/blob/c7fbab2b1bb5e048389d9ca68aa83e7b7edaa759/.pre-commit-config.yaml#L56-L62

Thanks for the reference, we should consider this soon