chore: fix some comments (linera-io#3082)

## Motivation

<!--
Briefly describe the goal(s) of this PR.
-->

 fix some comments

## Proposal

<!--
Summarize the proposed changes and how they address the goal(s) stated
above.
-->

## Test Plan

<!--
Explain how you made sure that the changes are correct and that they
perform as intended.

Please describe testing protocols (CI, manual tests, benchmarks, etc) in
a way that others
can reproduce the results.
-->

## Release Plan

<!--
If this PR targets the `main` branch, **keep the applicable lines** to
indicate if you
recommend the changes to be picked in release branches, SDKs, and
hotfixes.

This generally concerns only bug fixes.

Note that altering the public protocol (e.g. transaction format, WASM
syscalls) or storage
formats requires a new deployment.
-->
- Nothing to do / These changes follow the usual release cycle.
- These changes should be backported to the latest `devnet` branch, then
    - be released in a new SDK,
    - be released in a validator hotfix.
- These changes should be backported to the latest `testnet` branch,
then
    - be released in a new SDK,
    - be released in a validator hotfix.
- Backporting is not possible but we may want to deploy a new `devnet`
and release a new
      SDK soon.

## Links

<!--
Optional section for related PRs, related issues, and other references.

If needed, please create issues to track future improvements and link
them here.
-->
- [reviewer
checklist](https://github.com/linera-io/linera-protocol/blob/main/CONTRIBUTING.md#reviewer-checklist)

Signed-off-by: luchenhan <hanluchen@aliyun.com>

Author: luchenhan

examples/matching-engine/src/contract.rs

@@ -633,7 +633,7 @@ impl MatchingEngineContract {
     /// * Getting from the best matching price to the least good the price levels
     ///   are cleared.
     /// * That clearing creates a number of transfer orders.
-    /// * If after the level clearing the order is completely filled then it it not
+    /// * If after the level clearing the order is completely filled then it is not
     ///   inserted. Otherwise, it became a liquidity order in the matching engine
     async fn insert_and_uncross_market(
         &mut self,

linera-rpc/src/config.rs

@@ -112,7 +112,7 @@ pub struct ValidatorInternalNetworkPreConfig<P> {
     pub shards: Vec<ShardConfig>,
     /// The host name of the proxy on the internal network (IP or hostname).
     pub host: String,
-    /// The port the proxy listens on on the internal network.
+    /// The port the proxy listens on the internal network.
     pub port: u16,
     /// The host name of the proxy's metrics endpoint.
     pub metrics_host: String,

linera-views/src/views/map_view.rs

@@ -613,7 +613,7 @@ where
     /// shortened one by the prefix. The value is an enum that can be either a value
     /// or its serialization. This is needed in order to avoid a scenario where we
     /// deserialize something that was serialized. The key/value are send to the
-    /// function f. If it returns false the the loop ends prematurely. Keys and values
+    /// function f. If it returns false the loop ends prematurely. Keys and values
     /// are visited in the lexicographic order.
     async fn for_each_key_value_or_bytes_while<'a, F>(
         &'a self,