fix: migrate aws/credentials.go to use NewSession, same functionality but now supports error

[sspaink]

session.New is deprecated: Use NewSession functions to create sessions instead. NewSession has the same functionality as New except an error can be returned when the func is called instead of waiting to receive an error until a request is made.

The above is the exact message from the linter, noticed it was reporting that session.New was deprecated. Easy resolution is to replace it with NewSession and propagate the newly returned error. Found a little bit more info here: https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/sessions.html, but it just re-iterates the linter message that they deprecated New for better error handling.

[telegraf-tiger]

📦 Looks like new artifacts were built from this PR.

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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	freebsd_amd64.tar.gz	windows_i386.zip
armel.deb	armv6hl.rpm	freebsd_armv7.tar.gz
armhf.deb	linux_i386.tar.gzi386.rpm	freebsd_i386.tar.gz
i386.deb	ppc64le.rpm	linux_amd64.tar.gz
mips.deb	s390x.rpm	linux_arm64.tar.gz
mipsel.deb	x86_64.rpm	linux_armel.tar.gz
ppc64el.deb		linux_armhf.tar.gz
s390x.deb		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_s390x.tar.gz
		static_linux_amd64.tar.gz