chore: Simplify tracing with servo_tracing macro (#36661) (#37497)

This pull request refactors existing tracing annotations to leverage the
new `servo_tracing::instrument` macro introduced in #36573.

Specifically, the following transformations were applied:
- Removed `#[cfg_attr(feature = "tracing", ...)]` wrappers.
- Replaced `tracing::instrument` with `servo_tracing::instrument`.
- Removed `level = "trace"`
- Removed `fields(servo_profiling = true)` from tracing attributes
however retained others like `name`. `skip type`

Closes: #36661

---------

Signed-off-by: Bhuwan Pandit <bhuwanpandit109@gmail.com>
Signed-off-by: Jonathan Schwender <55576758+jschwe@users.noreply.github.com>
Co-authored-by: Jonathan Schwender <55576758+jschwe@users.noreply.github.com>

Cargo.lock

@@ -1104,6 +1104,7 @@ dependencies = [
  "net",
  "pixels",
  "profile_traits",
+ "servo-tracing",
  "servo_allocator",
  "servo_config",
  "servo_geometry",
@@ -1186,6 +1187,7 @@ dependencies = [
  "script_layout_interface",
  "script_traits",
  "serde",
+ "servo-tracing",
  "servo_config",
  "servo_rand",
  "servo_url",
@@ -2240,6 +2242,7 @@ dependencies = [
  "range",
  "read-fonts",
  "serde",
+ "servo-tracing",
  "servo_allocator",
  "servo_arc",
  "servo_config",
@@ -4251,6 +4254,7 @@ dependencies = [
  "script_layout_interface",
  "script_traits",
  "selectors",
+ "servo-tracing",
  "servo_arc",
  "servo_config",
  "servo_geometry",