Updated outdated HTTPX test matrix (#1917)

* Updated outdated httpx test matrix

Author: antonpirker

tox.ini

@@ -66,7 +66,7 @@ envlist =
     {py2.7,py3.5,py3.6,py3.7}-falcon-v{1.4}
     {py2.7,py3.5,py3.6,py3.7}-falcon-v{2.0}
     {py3.5,py3.6,py3.7,py3.8,py3.9}-falcon-v{3.0}
-    
+
     # FastAPI
     {py3.7,py3.8,py3.9,py3.10,py3.11}-fastapi
 
@@ -79,10 +79,12 @@ envlist =
     {py3.7}-gcp
 
     # HTTPX
-    {py3.6,py3.7,py3.8,py3.9,py3.10,py3.11}-httpx-v{0.16,0.17}
-    
+    {py3.6,py3.7,py3.8,py3.9}-httpx-v{0.16,0.17,0.18}
+    {py3.6,py3.7,py3.8,py3.9,py3.10}-httpx-v{0.19,0.20,0.21,0.22}
+    {py3.7,py3.8,py3.9,py3.10,py3.11}-httpx-v{0.23}
+
     # Huey
-    {py2.7,py3.5,py3.6,py3.7,py3.8,py3.9,py3.10,py3.11}-huey-2    
+    {py2.7,py3.5,py3.6,py3.7,py3.8,py3.9,py3.10,py3.11}-huey-2
 
     # OpenTelemetry (OTel)
     {py3.7,py3.8,py3.9,py3.10,py3.11}-opentelemetry
@@ -264,12 +266,19 @@ deps =
     flask-v2.0: Flask>=2.0,<2.1
 
     # HTTPX
+    httpx: pytest-httpx
     httpx-v0.16: httpx>=0.16,<0.17
     httpx-v0.17: httpx>=0.17,<0.18
-    
+    httpx-v0.18: httpx>=0.18,<0.19
+    httpx-v0.19: httpx>=0.19,<0.20
+    httpx-v0.20: httpx>=0.20,<0.21
+    httpx-v0.21: httpx>=0.21,<0.22
+    httpx-v0.22: httpx>=0.22,<0.23
+    httpx-v0.23: httpx>=0.23,<0.24
+
     # Huey
     huey-2: huey>=2.0
-    
+
     # OpenTelemetry (OTel)
     opentelemetry: opentelemetry-distro