Use regular lock for simplespanprocessor

[cijothomas]

Fixes #1409

Changes

Match SimpleSpanProcessor to align with SimpleLogRecordProcessor.
Still haven't addressed this yet.

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

Attention: Patch coverage is 85.41667% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 67.0%. Comparing base (a34c5ee) to head (dd80d8a).

❗ Current head dd80d8a differs from pull request most recent head 7596bac. Consider uploading reports for the commit 7596bac to get more accurate results

Files	Patch %	Lines
opentelemetry-sdk/src/trace/span_processor.rs	86.2%	4 Missing ⚠️
...ntelemetry-sdk/src/testing/trace/span_exporters.rs	84.2%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1612     +/-   ##
=======================================
- Coverage   67.0%   67.0%   -0.1%     
=======================================
  Files        138     138             
  Lines      19515   19479     -36     
=======================================
- Hits       13084   13058     -26     
+ Misses      6431    6421     -10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[TommyCpp]

Given the perf concern in #1409 I think it's worth call out explicitly in the comments of SimpleSpanProcessor that throughput may not be ideal and if one is looking for performance they should consider BatchSpanProcessor

[cijothomas]

Given the perf concern in #1409 I think it's worth call out explicitly in the comments of SimpleSpanProcessor that throughput may not be ideal and if one is looking for performance they should consider BatchSpanProcessor

added for span and log processor.

[TommyCpp]

LGTM!