Update VUnit to deal with nvc's --ignore-time option

[nathanaelhuffman]

Compiling into lib: ../hdl/ip/vhd/fmc_if/stm32h7_fmc_target.vhd        passed
** Warning: design unit LIB.STM32H7_FMC_TARGET_PKG is older than its source file /home/aaron/Oxide/git/quartz/hdl/ip/vhd/fmc_if/stm32h7_fmc_target_pkg.vhd and should be reanalysed
** Note: you can use the --ignore-time option to skip this check
** Warning: design unit LIB.CALC_PKG is older than its source file /home/aaron/Oxide/git/quartz/hdl/ip/vhd/utilities/calc_pkg.vhd and should be reanalysed

This was noticed with VUnit some time ago: nickg/nvc#179 but in order to properly fix, we need a new VUnit release that supports the nvc.global_options https://github.com/VUnit/vunit/blob/3032da050f11bdf038053f67fc664c39ee19f9f6/docs/news.d/948.feature.rst#L2

or we have to monkey-patch VUnit to enable this.

As reported by the VUnit maintainer, this seems to happen when doing git operations such as swapping branches etc which re-write the file times but don't affect content. VUnit does the correct thing here b/c it is looking at the file contents SHA, not the atime so this is mostly just annoying right now.