Updates for alpha.8

[martincostello]

• Update CHANGELOG.
• Bump samples to 8.0.0-alpha.8.

[codecov]

Codecov Report

Merging #1465 (bdf00ae) into main (e8c33db) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1465   +/-   ##
=======================================
  Coverage   83.89%   83.89%           
=======================================
  Files         275      275           
  Lines        6495     6495           
  Branches     1015     1015           
=======================================
  Hits         5449     5449           
  Misses        837      837           
  Partials      209      209           

Flag	Coverage Δ
linux	?
macos	83.89% <ø> (ø)
windows	83.89% <ø> (ø)

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