Enable `clippy::unnecessary_operation` (#8752)

Marshall Bowers created

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

Release Notes:

- N/A

Change summary

crates/collab/src/db/tests/contributor_tests.rs | 3 +--
crates/collab/src/db/tests/db_tests.rs          | 3 +--
tooling/xtask/src/main.rs                       | 1 -
3 files changed, 2 insertions(+), 5 deletions(-)

Detailed changes

crates/collab/src/db/tests/db_tests.rs 🔗

@@ -87,8 +87,7 @@ async fn test_get_or_create_user_by_github_account(db: &Arc<Database>) {
         },
     )
     .await
-    .unwrap()
-    .user_id;
+    .unwrap();
     let user_id2 = db
         .create_user(
             "user2@example.com",

tooling/xtask/src/main.rs 🔗

@@ -114,7 +114,6 @@ fn run_clippy(args: ClippyArgs) -> Result<()> {
         "clippy::single_range_in_vec_init",
         "clippy::suspicious_to_owned",
         "clippy::type_complexity",
-        "clippy::unnecessary_operation",
         "clippy::unnecessary_to_owned",
         "clippy::unnecessary_unwrap",
         "clippy::useless_conversion",