chore(ci): enabling partial flushing by default

[mawais54013]

Description

Enabling payload partial flush by default

Checklist

• [x] Title must conform to conventional commit.
• [x] Add additional sections for feat and fix pull requests.
• [x] Ensure tests are passing for affected code.
• [x] Library documentation and/or Datadog's documentation site is updated. Link to doc PR in description.

Reviewer Checklist

• [ ] Title is accurate.
• [ ] Description motivates each change.
• [ ] No unnecessary changes were introduced in this PR.
• [ ] PR cannot be broken up into smaller PRs.
• [ ] Avoid breaking API changes unless absolutely necessary.
• [ ] Tests provided or description of manual testing performed is included in the code or PR.
• [ ] Release note has been added for fixes and features, or else changelog/no-changelog label added.
• [ ] All relevant GitHub issues are correctly linked.
• [ ] Backports are identified and tagged with Mergifyio.
• [ ] Add to milestone.

[mawais54013]

Not sure why the integration tests are failing as in some cases, they do enable the partial flush but even setting partial_flush_enabled=False in functions like test_metrics and test_single_trace_too_large, they still seem to be failing.

Likewise, asyncio and ddtracerun do not use partial flush in their code so not sure if it's expected that they should be failing.

[codecov-commenter]

Codecov Report

Merging #4041 (64696bd) into 1.x (defa101) will decrease coverage by 0.04%. The diff coverage is 7.50%.

@@            Coverage Diff             @@
##              1.x    #4041      +/-   ##
==========================================
- Coverage   78.27%   78.23%   -0.05%     
==========================================
  Files         726      726              
  Lines       58268    58305      +37     
==========================================
+ Hits        45612    45614       +2     
- Misses      12656    12691      +35     

Impacted Files	Coverage Δ
tests/commands/test_runner.py	0.00% <ø> (ø)
tests/integration/test_integration.py	0.00% <0.00%> (ø)
ddtrace/tracer.py	88.85% <100.00%> (ø)
tests/contrib/asyncio/test_tracer_safety.py	100.00% <100.00%> (ø)
ddtrace/contrib/cassandra/session.py	87.84% <0.00%> (+1.10%)	:arrow_up:

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[Kyle-Verhoog]

Looks like the appsec test suite is failing on the last couple CI runs

[majorgreys]

Blocking for now until we have a handle on end-to-end testing of this feature.