chore: update msrv to 1.91.1

[nsarlin-zama]

closes: please link all relevant issues

PR content/description

Update msrv to 1.91.1.
To make this work, I also had to:

• update nightly toolchain (2025-11-19)
• update tfhe-lints toolchain

This does not include the update to remove the nightly feature, which will come in another pr.

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This change is 

[mayeul-zama]

Makefile line 433 at r1 (raw file):

		cargo "$(CARGO_RS_CHECK_TOOLCHAIN)" test --doc \
		--features=boolean,shortint,integer,zk-pok,pbs-stats,strings,experimental \
		-p tfhe -- --nocapture

Was "no capture" not working when passed in RUSTDOCFLAGS?

[nsarlin-zama]

Was "no capture" not working when passed in RUSTDOCFLAGS?

I don't know but now it does not build with this in the environment variable

[nsarlin-zama]

Reviewable status: 0 of 56 files reviewed, 1 unresolved discussion (waiting on @IceTDrinker, @mayeul-zama, @soonum, and @tmontaigu)

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Makefile line 433 at r1 (raw file):

Previously, mayeul-zama wrote…

Was "no capture" not working when passed in RUSTDOCFLAGS?

Now it does not build with this in the environment variable

[mayeul-zama]

Was "no capture" not working when passed in RUSTDOCFLAGS?

I don't know but now it does not build with this in the environment variable

I added a clippy warning in a doctest to see what happens.
The behavior the same as before.
Removing the "-- --nocapture" in the end of the line also works (with some difference: dots are green and the error is printed in the end instead of in the middle)

[IceTDrinker]

Thanks a lot !

@IceTDrinker reviewed 48 of 49 files at r1, 5 of 5 files at r2, 1 of 1 files at r3, 2 of 2 files at r4, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @mayeul-zama, @soonum, and @tmontaigu)

[nsarlin-zama]

Fix wasm build for this: rust-lang/rust#147225:

This will break current Web multi-threading users. To address this they can add the following RUSTFLAGS:
-Clink-args=--shared-memory,--max-memory=1073741824,--import-memory,--export=__wasm_init_tls,--export=__tls_size,--export=__tls_align,--export=__tls_base

The exact line does not work, had to split it into multiple -Clink-arg

[IceTDrinker]

Makefile line 655 at r5 (raw file):

	cd tfhe && \
	rustup component add rust-src --toolchain $(RS_CHECK_TOOLCHAIN) && \
	RUSTFLAGS="$(WASM_RUSTFLAGS) -C target-feature=+atomics,+bulk-memory -Clink-arg=--shared-memory -Clink-arg=--max-memory=1073741824 -Clink-arg=--import-memory -Clink-arg=--export=__wasm_init_tls -Clink-arg=--export=__tls_size -Clink-arg=--export=__tls_align -Clink-arg=--export=__tls_base" rustup run $(RS_CHECK_TOOLCHAIN) \

over several lines maybe ? 😅

[nsarlin-zama]

Reviewable status: 55 of 57 files reviewed, 1 unresolved discussion (waiting on @IceTDrinker, @mayeul-zama, @soonum, and @tmontaigu)

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Makefile line 655 at r5 (raw file):

Previously, IceTDrinker wrote…

over several lines maybe ? 😅

done

[pgardratzama]

I am not sure "is_multiple_of(2)" is better than "% 2 == 0" but it does not do any harm.
HPU related tests and noise measures using NTT are ok so let's go.
Thanks!!!

[IceTDrinker]

I am not sure "is_multiple_of(2)" is better than "% 2 == 0" but it does not do any harm. HPU related tests and noise measures using NTT are ok so let's go. Thanks!!!

agreed, the lints recommended it, it does not seem to harm the readability of our code so 🤷

[IceTDrinker]

Looks good !

@IceTDrinker reviewed 1 of 2 files at r5, 1 of 1 files at r6, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @mayeul-zama, @soonum, and @tmontaigu)