Profiler: fix build on Debian/Ubuntu

When linked with --as-needed, there needs to be an explicit reference to librt for the timing
api's used in the profiler.

Closes #121
5 jobs for 121-3-27-91-build-failure-on-debian-ubuntu in 14 minutes and 34 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Static Analysis
passed #8726
cppcheck

00:00:29

 
  Build
failed #8728
allowed to fail
fedora_clang

00:00:13

passed #8727
fedora_gcc

00:03:00

 
  Thorough Tests
passed #8729
coverage

00:10:50

73.1%
 
  Failure
skipped #8730
on_failure
 
Name Stage Failure
failed
fedora_clang Build
-- Set Environment --
cp: cannot stat '/cwd/.cache': No such file or directory
Uploading artifacts...
WARNING: /builds/GNOME/gjs/.cache/jhbuild/build/gjs/test-suite.log: no matching files
WARNING: /builds/GNOME/gjs/.cache/jhbuild/build/gjs/config.log: no matching files
WARNING: /builds/GNOME/gjs/.cache/jhbuild/build/gjs/Makefile: no matching files
/builds/GNOME/gjs/coverage/: found 3 matching files

Uploading artifacts to coordinator... ok
id=8728 responseStatus=201 Created token=yxcxsPGL
ERROR: Job failed: exit code 1