Bump tox from 4.28.0 to 4.28.3

changes/2416.misc.rst

@@ -0,0 +1 @@
+Updated tox from 4.28.0 to 4.28.3.

docs/how-to/x11passthrough.rst

@@ -191,7 +191,7 @@ on the host machine for the display.
 TCP Proxy
 ~~~~~~~~~
 
-The `socat <https://repo.or.cz/socat.git>`__ tool is a widely available program
+The `socat <http://www.dest-unreach.org/socat/>`__ tool is a widely available program
 to relay bi-directional data transfer between independent data channels. It
 allows running a process on the host to listen on a network port and send any
 received data to a socket connected to an X display on the other side.

pyproject.toml

@@ -105,7 +105,7 @@ dev = [
     "pytest == 8.4.1",
     "pytest-xdist == 3.8.0",
     "setuptools_scm == 8.3.1",
-    "tox == 4.28.0",
+    "tox == 4.28.3",
 ]
 # Docs are always built on a specific Python version; see RTD and tox config files,
 # and the docs contribution guide.