test: Mark more online tests (#4595)

Author: mgorny

crates/pixi/tests/integration_rust/add_tests.rs

@@ -83,6 +83,7 @@ async fn add_functionality() {
 
 /// Test adding a package with a specific channel
 #[tokio::test]
+#[cfg_attr(not(feature = "online_tests"), ignore)]
 async fn add_with_channel() {
     setup_tracing();
 

crates/pixi/tests/integration_rust/pypi_tests.rs

@@ -16,6 +16,7 @@ use crate::setup_tracing;
 /// before when running `pixi list -e all`, this would have not included numpy
 /// we are now explicitly testing that this works
 #[tokio::test]
+#[cfg_attr(not(feature = "online_tests"), ignore)]
 async fn pyproject_optional_dependencies_resolve_recursively() {
     setup_tracing();