fixup! 🚧(project) remove Python 3.8 support

pyproject.toml

@@ -56,7 +56,7 @@ backend-ldp = [
     "requests>=2.0.0",
 ]
 backend-lrs = [
-    "httpx==0.27.2",
+    "httpx<0.27.3", # pin as `pytest-httpx<0.23.0` requires `httpx==0.24.*`
 ]
 backend-mongo = [
     "motor[srv]>=3.3.0",
@@ -104,9 +104,9 @@ dev = [
     "polyfactory==2.16.2",
     "pyfakefs==5.6.0",
     "pymdown-extensions==10.9",
-    "pytest==8.3.3", 
+    "pytest<8.0.0", # pin as pytest-httpx<0.23.0 is not compatible with pytest 8.0.0
     "pytest-cov==5.0.0",
-    "pytest-httpx==0.30.0",
+    "pytest-httpx<0.23.0", # pin as Python 3.8 is no longer supported from release 0.23.0
     "requests-mock==1.12.1",
     "responses==0.25.3",
     "ruff==0.6.5",
@@ -119,7 +119,7 @@ lrs = [
     "bcrypt==4.2.0",
     "fastapi==0.114.2",
     "cachetools==5.5.0",
-    "httpx==0.27.2", # pin as `pytest-httpx<0.23.0` requires `httpx==0.24.*`
+    "httpx<0.27.3", # pin as `pytest-httpx<0.23.0` requires `httpx==0.24.*`
     "sentry_sdk==2.14.0",
     "python-jose==3.3.0",
     "uvicorn[standard]==0.30.6",