CHANGE: Remove version defines for profiling.

[surfnerd]

Description

Remove the version defines for profiling. The changelog does not need to change since there are no functional changes here.

Changes made

The profiling.core package is not needed, just use the Unity.Profiling.ProfilerMarker from the main assembly.

Testing

Tested locally.

Risk

Low risk.

Checklist

Before review:

~~- [ ] Changelog entry added.

• Explains the change in Changed, Fixed, Added sections.
• For API change contains an example snippet and/or migration example.
• JIRA ticket linked, example (case %%). If it is a private issue, just add the case ID without a link.
• Jira port for the next release set as "Resolved".~~ ~~- [ ] Tests added/changed, if applicable.
• Functional tests Area_CanDoX, Area_CanDoX_EvenIfYIsTheCase, Area_WhenIDoX_AndYHappens_ThisIsTheResult.
• Performance tests.
• Integration tests.~~ ~~- [ ] Docs for new/changed API's.
• Xmldoc cross references are set correctly.
• Added explanation how the API works.
• Usage code examples added.
• The manual is updated, if needed.~~

During merge:

• [x] Commit message for squash-merge is prefixed with one of the list:
  • NEW: ___.
  • FIX: ___.
  • DOCS: ___.
  • CHANGE: ___.
  • RELEASE: 1.1.0-preview.3.

After merge:

• [ ] Create forward/backward port if needed. If you are blocked from creating a forward port now please add a task to ISX-1444.

[surfnerd]

Thanks for this PR @surfnerd. Code changes look good to me. We just need to make sure it works fine for the Input System supported Unity range (2019 LTS and forward).

Hey @ekcoh, FYI I tested 2019.4 and Unity 6 locally.

[surfnerd]

based on the new Info i may need to keep the indirection. please don't merge yet

[surfnerd]

@ekcoh @Pauliusd01, this is good to go in terms of merging. I just wanted to do an extra check. I appreciate your patience!