Allow escaped let as expression

[HalidOdat]

Fixes: https://github.com/tc39/test262/blob/72c0c5e16350a76bd41f7a1ceb7702588a2a39c6/test/language/statements/let/syntax/escaped-let.js

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	94,657	94,657	0
Passed	73,887	73,888	+1
Ignored	17,505	17,505	0
Failed	3,265	3,264	-1
Panics	0	0	0
Conformance	78.06%	78.06%	+0.00%

Fixed tests (1):

test/language/statements/let/syntax/escaped-let.js (previously Failed)

[codecov]

Codecov Report

Merging #2916 (1a3118f) into main (7605453) will increase coverage by 0.00%.
The diff coverage is 25.00%.

@@           Coverage Diff           @@
##             main    #2916   +/-   ##
=======================================
  Coverage   51.96%   51.96%           
=======================================
  Files         431      431           
  Lines       43657    43653    -4     
=======================================
- Hits        22686    22685    -1     
+ Misses      20971    20968    -3     

Impacted Files	Coverage Δ
boa_parser/src/parser/statement/expression/mod.rs	27.27% <0.00%> (+1.74%)	⬆️
boa_parser/src/parser/statement/mod.rs	61.31% <33.33%> (+0.13%)	⬆️

... and 1 file with indirect coverage changes

[jedel1043]

Good catch!

[Razican]

Thanks!