feat(EXC-1860): Increase Wasm64 heap size to 6 GiB (#3748)

This PR increases the Wasm64 heap size to 6 GiB.

rs/embedders/tests/wasmtime_embedder.rs

@@ -3077,7 +3077,7 @@ fn large_wasm64_memory_allocation_test() {
 
     let mut config = ic_config::embedders::Config::default();
     config.feature_flags.wasm64 = FlagStatus::Enabled;
-    let max_heap_size_in_pages = config.max_wasm_memory_size.get() / WASM_PAGE_SIZE as u64;
+    let max_heap_size_in_pages = config.max_wasm64_memory_size.get() / WASM_PAGE_SIZE as u64;
     let wat = format!(
         r#"
     (module

rs/execution_environment/src/execution/install_code/tests.rs

@@ -21,7 +21,7 @@ use ic_test_utilities_execution_environment::{
 };
 use ic_test_utilities_metrics::fetch_int_counter;
 use ic_types::messages::MessageId;
-use ic_types::{ingress::WasmResult, MAX_STABLE_MEMORY_IN_BYTES, MAX_WASM_MEMORY_IN_BYTES};
+use ic_types::{ingress::WasmResult, MAX_MEMORY_ALLOCATION};
 use ic_types_test_utils::ids::user_test_id;
 use ic_types_test_utils::ids::{canister_test_id, subnet_test_id};
 use ic_universal_canister::{call_args, wasm, UNIVERSAL_CANISTER_WASM};
@@ -91,7 +91,7 @@ fn install_code_fails_on_invalid_memory_allocation() {
     assert_eq!(
         format!(
             "MemoryAllocation expected to be in the range [0..{}], got 18_446_744_073_709_551_615",
-            candid::Nat((MAX_STABLE_MEMORY_IN_BYTES + MAX_WASM_MEMORY_IN_BYTES).into())
+            candid::Nat(MAX_MEMORY_ALLOCATION.get().into())
         ),
         err.description()
     );

rs/types/types/src/lib.rs

@@ -492,7 +492,7 @@ pub const MAX_WASM_MEMORY_IN_BYTES: u64 = 4 * GIB;
 /// The upper limit on the Wasm64 canister memory size.
 /// This constant is used by other crates to define other constants, that's why
 /// it is public and `u64` (`NumBytes` cannot be used in const expressions).
-pub const MAX_WASM64_MEMORY_IN_BYTES: u64 = 4 * GIB;
+pub const MAX_WASM64_MEMORY_IN_BYTES: u64 = 6 * GIB;
 
 const MIN_MEMORY_ALLOCATION: NumBytes = NumBytes::new(0);
 pub const MAX_MEMORY_ALLOCATION: NumBytes =