Remove connection_id from ViewContext (#3464)

# Description of Changes

<!-- Please describe your change, mention any related tickets, and so on
here. -->

Removing `connection_id` from `ViewContext` for performance reasons. We
intend to wait to hear from clients before assuming that it's necessary
to include.

# API and ABI breaking changes

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corresponding GitHub label. -->

None (unreleased feature)

# Expected complexity level and risk

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0

# Testing

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reviewers to do,
so that you're confident that all the changes work as expected! -->

n/a

Author: joshua-spacetime

crates/bindings/src/lib.rs

@@ -806,7 +806,6 @@ pub struct AnonymousViewContext {
 /// Use this type if the view depends on the caller's identity.
 pub struct ViewContext {
     pub sender: Identity,
-    pub connection_id: Option<ConnectionId>,
     pub db: LocalReadOnly,
 }
 
@@ -943,7 +942,6 @@ impl ReducerContext {
     pub fn as_read_only(&self) -> ViewContext {
         ViewContext {
             sender: self.sender,
-            connection_id: self.connection_id,
             db: LocalReadOnly {},
         }
     }

crates/bindings/src/rt.rs

@@ -807,8 +807,6 @@ extern "C" fn __call_view__(
     sender_1: u64,
     sender_2: u64,
     sender_3: u64,
-    conn_id_0: u64,
-    conn_id_1: u64,
     args: BytesSource,
     sink: BytesSink,
 ) -> i16 {
@@ -817,29 +815,12 @@ extern "C" fn __call_view__(
     let sender: [u8; 32] = bytemuck::must_cast(sender);
     let sender = Identity::from_byte_array(sender); // The LITTLE-ENDIAN constructor.
 
-    // Piece together `conn_id_i` into a `ConnectionId`.
-    // The all-zeros `ConnectionId` (`ConnectionId::ZERO`) is interpreted as `None`.
-    let conn_id = [conn_id_0, conn_id_1];
-    let conn_id: [u8; 16] = bytemuck::must_cast(conn_id);
-    let conn_id = ConnectionId::from_le_byte_array(conn_id); // The LITTLE-ENDIAN constructor.
-    let conn_id = (conn_id != ConnectionId::ZERO).then_some(conn_id);
-
     let views = VIEWS.get().unwrap();
     let db = LocalReadOnly {};
-    let connection_id = conn_id;
 
     write_to_sink(
         sink,
-        &with_read_args(args, |args| {
-            views[id](
-                ViewContext {
-                    sender,
-                    connection_id,
-                    db,
-                },
-                args,
-            )
-        }),
+        &with_read_args(args, |args| views[id](ViewContext { sender, db }, args)),
     );
     0
 }