Enable clippy::explicit_counter_loop (#8776)

This PR enables the
[`clippy::explicit_counter_loop`](https://rust-lang.github.io/rust-clippy/master/index.html#/explicit_counter_loop)
rule and fixes the outstanding violations.

Release Notes:

- N/A

tooling/xtask/src/main.rs

@@ -89,7 +89,6 @@ fn run_clippy(args: ClippyArgs) -> Result<()> {
         "clippy::derivable_impls",
         "clippy::derive_ord_xor_partial_ord",
         "clippy::eq_op",
-        "clippy::explicit_counter_loop",
         "clippy::implied_bounds_in_impls",
         "clippy::iter_kv_map",
         "clippy::iter_overeager_cloned",