Update the base image to Fedora 40

Author: frenzymadness

README.md

@@ -62,6 +62,11 @@ Until version 0.4, this action always used the latest [fedora-python-tox](https:
 image. Since version 34.0, the first number in the version (also sometimes
 referred to as the "major version") represents the release of Fedora used in the image.
 
+### v40.0
+
+* Uses Fedora 40 as the base container image.
+* Python 3.7 is no longer available.
+
 ### v39.0
 
 * Uses Fedora 39 as the base container image.

action.yaml

@@ -16,7 +16,7 @@ inputs:
 
 runs:
   using: docker
-  image: docker://fedorapython/fedora-python-tox:f39
+  image: docker://fedorapython/fedora-python-tox:f40
   env:
     TOXENV: ${{ inputs.tox_env }}
     DNF_INSTALL: ${{ inputs.dnf_install }}