utils: Avoid a potential build failure due to undefined M_PI constant

The <math.h> header needs to be included.

Previously I suppose libtracker-sparql.h pulled this in.

!148
1 job for wip/rishi/define-m-pi in 14 minutes and 16 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #891917
flatpak
flatpak

00:14:16