Update nasm-rs to 0.3.0

[FreezyLemon]

nasm-rs versions before 0.3 ignored the number of jobs set by cargo's job server. This means that even with cargo b -j1 or NUM_JOBS=1 cargo b, the rav1e build script uses 100% CPU.

[FreezyLemon]

Also bumped jobserver while I'm at it. It has some small safety improvements.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.72%. Comparing base (3c3a26f) to head (2ffac65).
Report is 20 commits behind head on master.

❗ Current head 2ffac65 differs from pull request most recent head 96beb31

Please upload reports for the commit 96beb31 to get more accurate results.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3383      +/-   ##
==========================================
+ Coverage   88.52%   88.72%   +0.20%     
==========================================
  Files          89       89              
  Lines       28323    27753     -570     
==========================================
- Hits        25074    24625     -449     
+ Misses       3249     3128     -121     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.