Remove `near-o11y` nearcore metric dep wrapper

[DSharifi]

Background

We depend on nearcore's prometheus wrapper. It's only used in a few metrics and should be removed such that we use the prometheus crate directly as in our all other metrics.

mpc/crates/node/src/metrics.rs

Lines 17 to 48 in 59bb866

	pub static MPC_TRIPLES_GENERATION_TIME_ELAPSED: LazyLock<prometheus::Histogram> =
	LazyLock::new(|| {
	near_o11y::metrics::try_create_histogram(
	"near_mpc_triples_generation_time_elapsed",
	"Time taken to generate a batch of triples",
	)
	.unwrap()
	});
	pub static MPC_PRE_SIGNATURE_TIME_ELAPSED: LazyLock<prometheus::Histogram> = LazyLock::new(|| {
	near_o11y::metrics::try_create_histogram(
	"near_mpc_pre_signature_time_elapsed",
	"Time taken to generate a pre signature",
	)
	.unwrap()
	});
	pub static MPC_SIGNATURE_TIME_ELAPSED: LazyLock<prometheus::Histogram> = LazyLock::new(|| {
	near_o11y::metrics::try_create_histogram(
	"near_mpc_signature_time_elapsed",
	"Time taken to generate a signature",
	)
	.unwrap()
	});
	pub static MPC_CKD_TIME_ELAPSED: LazyLock<prometheus::Histogram> = LazyLock::new(|| {
	near_o11y::metrics::try_create_histogram(
	"near_mpc_ckd_time_elapsed",
	"Time taken to generate a confidential key",
	)
	.unwrap()
	});

User Story

No response

Acceptance Criteria

remove near-o11y from the workspace and use prometheus directly for the metrics that rely on it.

Resources & Additional Notes

No response