chore: mark casts as able to be deduplicated

[TomAFrench]

Description

Problem*

Resolves

Summary*

Casts can always be deduplicated as they have no ACIRgen footprint anyway.

Additional Context

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Execution Report

Program	Execution Time	%
sha256_regression	0.055s	1%
regression_4709	0.001s	0%
ram_blowup_regression	0.573s	-1%
rollup-root	0.105s	0%
rollup-block-merge	0.105s	0%
rollup-base-public	1.330s	0%
rollup-base-private	0.512s	-1%
private-kernel-tail	0.022s	0%
private-kernel-reset	0.391s	1%
private-kernel-inner	0.097s	0%

[github-actions]

Compilation Report

Program	Compilation Time	%
sha256_regression	1.020s	-16%
regression_4709	0.771s	-10%
ram_blowup_regression	14.940s	-3%
rollup-root	3.430s	-9%
rollup-block-merge	4.010s	14%
rollup-base-public	29.000s	-8%
rollup-base-private	10.900s	-8%
private-kernel-tail	1.072s	4%
private-kernel-reset	8.534s	-2%
private-kernel-inner	2.104s	-1%

[github-actions]

Execution Memory Report

Program	Peak Memory
keccak256	74.65M
workspace	123.86M
regression_4709	315.98M
ram_blowup_regression	512.41M
rollup-base-public	492.17M
rollup-base-private	332.25M
private-kernel-tail	181.08M
private-kernel-reset	254.94M
private-kernel-inner	212.77M

[github-actions]

Compilation Memory Report

Program	Peak Memory
keccak256	78.55M
workspace	123.44M
regression_4709	422.96M
ram_blowup_regression	1.58G
rollup-base-public	2.55G
rollup-base-private	1.24G
private-kernel-tail	200.40M
private-kernel-reset	728.14M
private-kernel-inner	290.46M