Add build isolation logging to build operations (#7169)

## Summary

Closes #7154.

crates/uv-build/src/lib.rs

@@ -504,6 +504,8 @@ impl SourceBuild {
  // Setup the build environment. If build isolation is disabled, we assume the build
  // environment is already setup.
  if build_isolation.is_isolated(package_name) {
+ debug!("Resolving build requirements");
+
  let resolved_requirements = Self::get_resolved_requirements(
  build_context,
  source_build_context,
@@ -518,6 +520,8 @@ impl SourceBuild {
  .map_err(|err| {
  Error::RequirementsInstall("`build-system.requires` (install)", err)
  })?;
+ } else {
+ debug!("Proceeding without build isolation");
  }
 
  // Figure out what the modified path should be
@@ -554,6 +558,8 @@ impl SourceBuild {
  // environment is already setup.
  let runner = PythonRunner::new(concurrent_builds, level);
  if build_isolation.is_isolated(package_name) {
+ debug!("Creating PEP 517 build environment");
+
  create_pep517_build_environment(
  &runner,
  &source_tree,