Bump MSRV to match clap dependency

[rukai]

Since clap 4.4 bumped its MSRV to 1.70 inferno no longer builds on 1.64 and needs minimum 1.70 This PR:

• bumps inferno's MSRV to 1.70
• makes use of a new stdlib API in 1.70 to drop the is-terminal and rustix dependencies.
  • This was also cargo's motivation for bumping MSRV which is how I noticed we could do the same here.

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (5d88bc3) 91.01% compared to head (8af0614) 91.01%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #301 +/- ## ======================================= Coverage 91.01% 91.01% ======================================= Files 19 19 Lines 4385 4385 ======================================= Hits 3991 3991 Misses 394 394 ``` | [Files Changed](https://app.codecov.io/gh/jonhoo/inferno/pull/301?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jon+Gjengset) | Coverage Δ | | |---|---|---| | [src/collapse/mod.rs](https://app.codecov.io/gh/jonhoo/inferno/pull/301?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Jon+Gjengset#diff-c3JjL2NvbGxhcHNlL21vZC5ycw==) | `96.96% <ø> (ø)` | |

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[rukai]

Understandable, I'll mark this as draft so it's around when it's needed.