ci: Run system tests in a separate namespace. #2030

Job	Run time
linux rpm fedora	4m 30s
dpdk gcc	8s
osx clang --disable-ssl	4m 47s
linux deb no dpdk	4m 29s
clang-analyze	18m 16s
linux gcc --disable-ssl	2m 18s
linux clang --disable-ssl	2m 27s
linux gcc c99	2m 19s
linux clang c99	2m 19s
linux gcc test	8m 16s
linux clang address,undefined test	15m 55s
linux gcc test --enable-shared	11m 15s
linux clang test --enable-shared	10m 49s
linux gcc check check-dpdk dpdk	16m 42s
linux clang check check-dpdk dpdk	16m 40s
linux gcc test -ljemalloc	8m 47s
linux clang test -ljemalloc	8m 28s
linux gcc --enable-afxdp	2m 17s
linux clang --enable-afxdp	2m 27s
linux gcc dpdk --enable-shared	3m 14s
linux clang dpdk --enable-shared	3m 17s
linux gcc dpdk-shared	2m 34s
linux clang dpdk-shared	2m 43s
linux gcc dpdk-shared --enable-shared	3m 24s
linux clang dpdk-shared --enable-shared	3m 20s
linux gcc m32 --disable-ssl	2m 53s
linux gcc check-ovsdb-cluster	6m 19s
linux gcc check-kernel -100	8m 29s
linux gcc check-kernel 100-	8m 52s
linux clang address,undefined check-kernel -100	10m 55s
linux clang address,undefined check-kernel 100-	11m 39s
linux gcc check-offloads -100	8m 57s
linux gcc check-offloads 100-	7m 0s
linux gcc dpdk check-system-userspace	10m 25s
linux clang address,undefined dpdk check-system-userspace	14m 7s
linux gcc dpdk check-system-tso	10m 12s
linux gcc dpdk check-afxdp	10m 45s
	4h 32m 14s

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