Ensure that "-000000" is an invalid extended year

[jessealama]

References:

• Is "-000000" a valid extended year format? #1753

[codecov]

Codecov Report

Merging #1997 (6213db9) into main (2a81fbc) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1997   +/-   ##
=======================================
  Coverage   95.00%   95.00%           
=======================================
  Files          19       19           
  Lines       10990    10990           
  Branches     1600     1600           
=======================================
  Hits        10441    10441           
  Misses        532      532           
  Partials       17       17           

Flag	Coverage Δ
test262	79.26% <ø> (ø)
tests	89.90% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2a81fbc...6213db9. Read the comment docs.

[jessealama]

closing because this is effectively a duplicate of PR #1992