fix(inputs.diskio): Update path to in /sys

[powersj]

Summary

Update default path from /sys/block to /sys/class/block. This change was made to the kernel 16 years ago and is the default location: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=edfaa7c36574f1bf09c65ad602412db9da5f96bf

Checklist

• No AI generated code was used in this PR

Related issues

resolves #15151

[telegraf-tiger]

Download PR build artifacts for linux_amd64.tar.gz, darwin_arm64.tar.gz, and windows_amd64.zip.
Downloads for additional architectures and packages are available below.

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Artifact URLs

DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz

[sheyabernstein]

Thank you @powersj

[srebhan]

LGTM. We could add a fallback to the old path, but given that this change was made 16y ago I think we should skip that until issues arise...