Allow to specify nanoseconds to timestamp in Starlark Processor

[essobedo]

Required for all PRs:

• Updated associated README.md.
• Wrote appropriate unit tests.

resolves #9104

Motivation

The upstream project starlark-go has added the support of nanoseconds in timestamp in the time module, thus the goal of this feature request is to provide the support of this new feature in the Starlark Processor.

Modifications

• Upgrade the version of go.starlark.net
• Add a test showing how to create a timestamp with nanoseconds
• Refer the test into the README.md

[telegraf-tiger]

🤝 ✅ CLA has been signed. Thank you!

[telegraf-tiger]

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• aarch64.rpm

• armel.rpm

• armv6hl.rpm

• i386.rpm

• ppc64le.rpm

• s390x.rpm

• x86_64.rpm

• darwin_amd64.tar.gz

• freebsd_amd64.tar.gz

• freebsd_i386.tar.gz

• linux_amd64.tar.gz

• linux_arm64.tar.gz

• linux_armel.tar.gz

• linux_armhf.tar.gz

• linux_i386.tar.gz

• linux_mips.tar.gz

• linux_mipsel.tar.gz

• linux_ppc64le.tar.gz

• linux_s390x.tar.gz

• static_linux_amd64.tar.gz

• windows_amd64.zip

• windows_i386.zip

• amd64.deb

• arm64.deb

• armel.deb

• armhf.deb

• i386.deb

• mips.deb

• mipsel.deb

• ppc64el.deb

• s390x.deb