Cache cargo-tarpaulin binary

[jedel1043]

Testing if this change improves CI times for the codecov check.

Had to use another cargo-install action because the original actions-rs/cargo-install is apparently unmaintained, and users were reporting problems with the cache (actions-rs/install#12)

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	94,842	94,842	0
Passed	74,691	74,691	0
Ignored	18,812	18,812	0
Failed	1,339	1,339	0
Panics	0	0	0
Conformance	78.75%	78.75%	0.00%

[jasonwilliams]

LGTM, shame about actions-rs being unmaintained

[jedel1043]

Let's see if the binary is correctly cached...

[jedel1043]

Nice! This should reduce our CI times by 3-5 minutes, which is the time it takes to compile tarpaulin

[codecov]

Codecov Report

Merging #3071 (df4e367) into main (d0fa8cb) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##             main    #3071   +/-   ##
=======================================
  Coverage   50.43%   50.43%           
=======================================
  Files         445      445           
  Lines       45910    45910           
=======================================
  Hits        23154    23154           
  Misses      22756    22756           

Impacted Files	Coverage Δ
boa_wasm/src/lib.rs	0.00% <0.00%> (ø)

... and 1 file with indirect coverage changes

[HalidOdat]

Looks good to me! :)