Update tox.ini

Signed-off-by: Jason Parraga <sovietaced@gmail.com>

Author: Sovietaced

tox.ini

@@ -86,7 +86,7 @@ envlist =
     tracecontext
     mypy,mypyinstalled
     docs
-    docker-tests-proto{3,4}
+    docker-tests-proto{3,4,5}
     public-symbols-check
 
 [testenv]
@@ -275,7 +275,7 @@ commands_pre =
 commands =
   {toxinidir}/scripts/tracecontext-integration-test.sh
 
-[testenv:docker-tests-proto{3,4}]
+[testenv:docker-tests-proto{3,4,5}]
 deps =
   pytest==7.1.3
   # Pinning PyYAML for issue: https://github.com/yaml/pyyaml/issues/724
@@ -288,6 +288,7 @@ deps =
   ; proto 3 and 4 tests install the respective version of protobuf
   proto3: protobuf~=3.19.0
   proto4: protobuf~=4.0
+  proto5: protobuf~=5.26.0
 
 changedir =
   tests/opentelemetry-docker-tests/tests