fix(processors.starlark): Avoid negative refcounts for tracking metrics

[srebhan]

Summary

Tracking metrics are currently aggressively accepted and dropped by the starlark processor. In turn, those metrics might be double tagged (accept or drop) especially in cases where we use the deepcopy starlark command. Moreover, the current testutil.Accumulator implementation just strips the tracking information and thus those errors have gone unnoticed in the tests.

This PR fixes the testutil.Accumulator implementation to mimic the behavior of the actual accumulator and uncover refcount or unacknowledged-metric issues. The PR also modifies the starlark processor to not accept metrics but leaves this to the output plugins. To be on the safe-side, deepcopys are modified to strip the tracking information by default as metrics might be deep-copied and then dropped, which will go unnoticed by the processor . To keep the tracking information an optional track parameter is added to deepcopy.

Checklist

• No AI generated code was used in this PR
• Unit-tests
• Updated documentation

Related issues

resolves #14360
superseeds #14372

[telegraf-tiger]

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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

[powersj]

Thanks for helping with this one!