update node exporter to 1.8.1 #143

Job	Run time
test-osx	35s
test-win	6m 4s
test	7m 2s
get-version	12s
dist-linux-osx	34s
build-win (windows, i386)	1m 10s
build-osx (darwin, x86_64)	56s
build-win (windows, x86_64)	1m 13s
build (linux, i386)	47s
build-osx (darwin, aarch64)	30s
build (linux, x86_64)	27s
dist-win	43s
build (linux, aarch64)	27s
build (freebsd, i386)	31s
build (freebsd, x86_64)	26s
build-win (windows, aarch64)	1m 15s
build (freebsd, aarch64)	24s
pkg-deb (linux, i386)	53s
pkg-deb (linux, x86_64)	1m 20s
pkg-rpm (linux, i386)	17s
pkg-rpm (linux, x86_64)	24s
pkg-deb (linux, aarch64)	50s
pkg-rpm (linux, aarch64)	19s
pkg-osx (darwin, x86_64)	28s
pkg-osx (darwin, aarch64)	24s
sign-win (windows, i386)	25s
sign-win (windows, x86_64)	24s
sign-win (windows, aarch64)	21s
integration-test-osx (darwin, x86_64)	37s
pkg-msi (windows, i386)	46s
pkg-msi (windows, x86_64)	45s
pkg-msi (windows, aarch64)	54s
integration-test-linux (linux, x86_64)	52s
clean-tmp-files (linux, i386)	2s
clean-tmp-files (linux, x86_64)	2s
clean-tmp-files (linux, aarch64)	2s
integration-test-windows (windows, x86_64)	3m 7s
clean-tmp-dist	4s
clean-tmp-winbin (windows, i386)	4s
clean-tmp-winbin (windows, x86_64)	4s
clean-tmp-winbin (windows, aarch64)	4s
make-release	0s
upload-linux-rpm-assets	0s
upload-windows-release-assets	0s
upload-linux-deb-assets	0s
upload-binary-release-assets	0s
upload-osx-pkg-assets	0s
	36m 44s

Provide feedback