WIP on a memory leak fix

[yuzefovich]

Epic: None

[blathers-crl[bot]]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

_{:owl: Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

[cockroach-teamcity]

This change is 

[yuzefovich]

This is RFAL. I'm including the last commit as a proof-of-concept, but I'm currently leaning towards not merging it.

[yuzefovich]

Thanks for all the reviews around the BytesMonitor infra! This is the last improvement I had in mind.

bors r+

[craig[bot]]

Build failed:

• unit_tests

[rickystewart]

bors r+

[craig[bot]]

Build succeeded:

• windows_build
• linux_amd64_fips_build
• lint
• docker_image_amd64
• unit_tests
• macos_arm64_build
• check_generated_code
• local_roachtest_fips
• linux_amd64_build
• macos_amd64_build
• acceptance
• local_roachtest
• linux_arm64_build
• examples_orms