[CODE HEALTH] clang-tidy `cppcoreguidelines-pro-type-const-cast` warnings

[dbarker]

This issue covers resolving the cppcoreguidelines-pro-type-const-cast warnings.

clang-tidy warnings (click to expand)

File	Line	Message
opentelemetry-cpp/examples/http/server.cc	55	do not use const_cast to remove const qualifier
opentelemetry-cpp/ext/include/opentelemetry/ext/http/client/curl/http_operation_curl.h	297	do not use const_cast to remove const qualifier
opentelemetry-cpp/ext/src/http/client/curl/http_operation_curl.cc	915	do not use const_cast to remove const qualifier
opentelemetry-cpp/ext/src/http/client/curl/http_operation_curl.cc	957	do not use const_cast to remove const qualifier
opentelemetry-cpp/ext/src/http/client/curl/http_operation_curl.cc	1005	do not use const_cast to remove const qualifier
opentelemetry-cpp/ext/test/w3c_tracecontext_http_test_server/main.cc	206	do not use const_cast to remove const qualifier
opentelemetry-cpp/sdk/include/opentelemetry/sdk/common/circular_buffer.h	43	do not use const_cast to remove const qualifier
opentelemetry-cpp/sdk/src/metrics/multi_observer_result.cc	68	do not use const_cast to remove const qualifier
opentelemetry-cpp/sdk/src/metrics/multi_observer_result.cc	109	do not use const_cast to remove const qualifier
opentelemetry-cpp/sdk/src/metrics/multi_observer_result.cc	132	do not use const_cast to remove const qualifier

Contributes to #2053

[github-actions]

This issue is available for anyone to work on. Make sure to reference this issue in your pull request.
✨ Thank you for your contribution! ✨

[Anish701]

Hi @dbarker, I would like to work on this fix as my first issue. Would you please be able to assign it to me? Thanks!

[Anish701]

Hi @dbarker, the PR for this issue passed the CI. Would you please be able to take a look whenever you get the chance? Thanks!
#4482