[auto] Update Rust toolchain to 1.75.0

[expressvpn-iat-bot]

Automated changes by create-pull-request GitHub action

[github-actions]

Code coverage summary for 1559a2f:

Filename                      Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
wolfssl-sys/src/lib.rs              7                 0   100.00%           4                 0   100.00%          26                 0   100.00%           0                 0         -
wolfssl/src/callback.rs             2                 2     0.00%           1                 1     0.00%           1                 1     0.00%           0                 0         -
wolfssl/src/context.rs            173                86    50.29%          52                16    69.23%         342               126    63.16%           0                 0         -
wolfssl/src/error.rs               21                 7    66.67%          12                 4    66.67%          49                 5    89.80%           0                 0         -
wolfssl/src/lib.rs                 64                16    75.00%          18                 6    66.67%          78                15    80.77%           0                 0         -
wolfssl/src/rng.rs                 20                 5    75.00%           5                 0   100.00%          48                 3    93.75%           0                 0         -
wolfssl/src/ssl.rs                471               199    57.75%          79                22    72.15%         995               263    73.57%           0                 0         -
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                             758               315    58.44%         171                49    71.35%        1539               413    73.16%           0                 0         -

✅ Region coverage 58% passes
✅ Line coverage 73% passes

[kp-mariappan-ramasamy]

Release notes:

https://blog.rust-lang.org/2023/12/28/Rust-1.75.0.html
https://doc.rust-lang.org/nightly/releases.html#version-1750-2023-12-28

Interesting changes:

• async fn in traits (Limitations)
• Cargo version changes (feat(toml): Allow version-less manifests rust-lang/cargo#12786)

[kp-mariappan-ramasamy]

• We do not have async_trait in public apis
• We have explicit version in Cargo.toml

No additional changes needed for the update

[kp-mariappan-ramasamy]

LGTM