Update .gitlab-ci.yml

1 job for master in 28 seconds (queued for 2 seconds)
Status Job ID Name Coverage
failed #54
alpine docker


Name Stage Failure
build Build There is an unknown failure, please try again
Package 'opus', required by 'virtual:world', not found

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively, you may set the environment variables DEPS_CFLAGS
and DEPS_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.
ERROR: Job failed: exit code 1