fix: gzip compressed envelopes

[jpnurmi]

The problem was originally noticed while experimenting with replacing sentry-native's curl transport with a .NET implementation for sentry-dotnet:

• feat: replace libcurl with .NET HttpClient for sentry-native sentry-dotnet#4222

The problem is also easy to reproduce by simply building sentry-native with SENTRY_TRANSPORT_COMPRESSION=ON, which results in:

Server stderr:
----------------------------------------
Exception occurred during processing of request from ('127.0.0.1', 55668)
Traceback (most recent call last):
  File "/usr/lib/python3.12/socketserver.py", line 692, in process_request_thread
    self.finish_request(request, client_address)
  File "/usr/lib/python3.12/socketserver.py", line 362, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/usr/lib/python3.12/socketserver.py", line 761, in __init__
    self.handle()
  File "/usr/lib/python3.12/http/server.py", line 436, in handle
    self.handle_one_request()
  File "/usr/lib/python3.12/http/server.py", line 424, in handle_one_request
    method()
  File "/home/jpnurmi/Projects/sentry/github-workflows/sentry-cli/integration-test/sentry-server.py", line 97, in do_POST
    sys.stdout.write(self.body)
TypeError: write() argument must be str, not bytes
----------------------------------------

[-] Console app NativeAOT (net8.0).Produces the expected exception (Native) 1.81s (1.81s|1ms)
 Expected $false, but got $true.
 at $result.HasErrors() | Should -BeFalse, /home/jpnurmi/Projects/sentry/sentry-dotnet/integration-test/runtime.Tests.ps1:172
 at <ScriptBlock>, /home/jpnurmi/Projects/sentry/sentry-dotnet/integration-test/runtime.Tests.ps1:172

[jpnurmi]

@vaind Is this something for you? :)

[bruno-garcia]

Looks like this broke the tests: https://github.com/getsentry/github-workflows/actions/runs/15377723000

Or at least coincidently

the 3 checks here look OK, diff PR

[bruno-garcia]

Because it wasn't a squash, but I see the failure here:

d2bdc9a