fix(profiling): re-accept interval for memory profile collector [backport 3.12] (#14485)

In #14205 we removed the `_interval` parameter for the
`MemoryCollector`.
This was a mistake. Now the memory profile collector thread basically
spins in a tight loop because the interval is 0. Add that parameter
back.

Backports #14276 to the 3.12 branch. This was fixed in 3.12.0 but
somehow didn't make it to 3.12.1 or 3.12.2

The actual fix was picked up by #14487 and this PR is mainly to add a
release note.

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [x] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

Co-authored-by: Taegyun Kim <taegyun.kim@datadoghq.com>

Author: nsrip-dd

releasenotes/notes/profiling-fix-memalloc-collector-spin-regression-97b4b8093a89c54f.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    profiling: This fixes a performance regression where the memory profiler's
+    collector thread would spin in a tight loop, consuming nearly a full CPU
+    core.