python3-pytest-cache: remove dead recipe

pytest-cache has been unmaintained since its last release in 2013 and
its functionality was long ago merged into pytest core. Drop the recipe
along with its packagegroup-meta-python entry and the now-redundant ptest
dependency in python3-fastjsonschema.

Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-python/recipes-core/packagegroups/packagegroup-meta-python.bb

@@ -343,7 +343,6 @@ RDEPENDS:packagegroup-meta-python3 = "\
     ${@bb.utils.contains("DISTRO_FEATURES", "systemd", "python3-pystemd", "", d)} \
     python3-pytest-asyncio \
     python3-pytest-benchmark \
-    python3-pytest-cache \
     python3-pytest-forked \
     python3-pytest-helpers-namespace \
     python3-pytest-html \