Tests: Update file(G_R_D) test to make system library optional

Since the system library may not exist on the filesystem on macOS
11, skip it if it doesn't exist.
32 jobs for !4998 with macos-11-file-GET_RUNTIME_DEPENDENCIES in 32 minutes and 14 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Build
manual #5072794
linux docker build manual
build:centos6-release
passed #5072791
linux docker build
build:debian10-iwyu

00:12:55

manual #5072795
linux-3.17 linux docker build manual
build:fedora31-ninja
passed #5072793
linux-3.17 linux docker build
build:fedora31-sphinx

00:18:10

passed #5072792
linux-3.17 linux docker build
build:fedora31-tidy

00:02:14

passed #5072797
nonconcurrent xcode-11.5 shell macos cmake manual
build:macos-makefiles

00:07:04

manual #5072796
nonconcurrent xcode-11.5 shell macos cmake manual
build:macos-ninja
manual #5072798
nonconcurrent msvc-19.25 vs2019 shell windows cmake manual
build:windows-vs2019-x64-ninja
 
  Test
created #5072799
linux-3.17 linux docker build
test:fedora31-ninja
passed #5072801
nonconcurrent xcode-11.5 shell macos cmake
test:macos-makefiles

00:21:31

created #5072800
nonconcurrent xcode-11.5 shell macos cmake
test:macos-ninja
created #5072802
nonconcurrent msvc-19.25 vs2019 shell windows cmake
test:windows-vs2019-x64-ninja
 
  Test Ext
created #5072804
linux docker cuda-rt
test:cuda10.2-nvidia
created #5072803
linux-3.17 linux docker build
test:fedora31-makefiles
created #5072805
linux-3.17 linux docker build
test:fedora31-ninja-multi
created #5072806
concurrent xcode-11.5 shell macos cmake
test:macos-xcode
created #5072807
concurrent msvc-19.25 vs2019 shell windows cmake
test:windows-vs2019-x64
 
  External
passed cdash

passed ghostflow-check-master

passed ghostflow-check-release

passed ghostflow-stager

passed cdash

passed cdash

passed cdash

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager