tacd: replace instances of x % N == 0 with x.is_multiple_of(N)

[hnez]

This is inspired by a recently added clippy lint:

 error: manual implementation of `.is_multiple_of()`
   --> src/dut_power.rs:248:16
    |
248 |             if N % 2 == 0 {
    |                ^^^^^^^^^^ help: replace with: `N.is_multiple_of(2)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_multiple_of
    = note: `-D clippy::manual-is-multiple-of` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::manual_is_multiple_of)]`

error: manual implementation of `.is_multiple_of()`
   --> src/ui/screens/diagnostics.rs:256:26
    |
256 |                 let on = self.led_cycle_state % 2 != 0;
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `!self.led_cycle_state.is_multiple_of(2)`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_multiple_of

This should fix the currently broken scheduled builds.

[hnez]

We have to postpone this until our rustc version is updated, since .is_multiple_of() was not yet stabilized in the rustc version in Yocto walnascar (1.87.0 vs 1.84.1).

See #102 for a a PR that just disables the lint for now.

[SmithChart]

LGTM. Let's wait for a compatible rustc in yocto and then we are good to go.