Make environments opcodes use varying operands

[HalidOdat]

Depends on #3332

Makes environment push opcodes that take index use varying operands, this required a bit of a refactor so we store environments pushed starting at zero, not in reversed order.

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	95,574	95,574	0
Passed	75,273	75,273	0
Ignored	19,482	19,482	0
Failed	819	819	0
Panics	0	0	0
Conformance	78.76%	78.76%	0.00%

[codecov]

Codecov Report

Attention: 12 lines in your changes are missing coverage. Please review.

Comparison is base (78bc9eb) 49.51% compared to head (175c434) 49.49%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3340      +/-   ##
==========================================
- Coverage   49.51%   49.49%   -0.03%     
==========================================
  Files         446      446              
  Lines       43777    43767      -10     
==========================================
- Hits        21678    21663      -15     
- Misses      22099    22104       +5     

Files	Coverage Δ
boa_engine/src/builtins/eval/mod.rs	64.44% <100.00%> (-0.40%)	⬇️
boa_engine/src/bytecompiler/declarations.rs	51.40% <100.00%> (+0.11%)	⬆️
boa_engine/src/bytecompiler/env.rs	94.87% <100.00%> (ø)
boa_engine/src/bytecompiler/function.rs	100.00% <100.00%> (ø)
boa_engine/src/bytecompiler/statement/block.rs	100.00% <100.00%> (ø)
boa_engine/src/bytecompiler/statement/loop.rs	75.10% <100.00%> (-1.17%)	⬇️
boa_engine/src/bytecompiler/statement/switch.rs	100.00% <100.00%> (ø)
boa_engine/src/bytecompiler/statement/try.rs	90.90% <100.00%> (-0.11%)	⬇️
boa_engine/src/bytecompiler/statement/with.rs	100.00% <100.00%> (ø)
boa_engine/src/vm/opcode/mod.rs	5.32% <ø> (ø)
... and 3 more

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[raskad]

Nice change!