Export ZERO_AR_DATE for macos linker invocations

Export ZERO_AR_DATE for macos linker invocations

This commit attempts to improve reproducibility of builds on macOS by
exporting the `ZERO_AR_DATE=1` environment variable for all invocations
of the linker. While it looks like this env var is targeted at just the
`ar` command (which does actually read this) it appears that recent-ish
versions of the linker *also* read this environment variable. This
env var forces the linker to set a deterministic zero value for the
mtime in the N_OSO field of the object file.

Currently it's believe that older versions of the linker will simply
ignore this env var, while newer versions will read it and produce a
deterministic output for compilations with debuginfo.

Closes #47086
Closes #66568