python3-backports-functional-lru-cache: remove, not needed for Python 3

This is a backport of the Python 3 lru_cache for Python 2 users, so
obviously it makes no sense to have for Python 3.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>

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

@@ -46,7 +46,6 @@ RDEPENDS:packagegroup-meta-python3 = "\
     python3-aws-iot-device-sdk-python \
     python3-babel \
     python3-backcall \
-    python3-backports-functools-lru-cache \
     python3-bandit \
     python3-bcrypt \
     python3-beautifulsoup4 \
@@ -482,7 +481,6 @@ RDEPENDS:packagegroup-meta-python3-ptest = "\
     python3-markupsafe-ptest \
     python3-ansicolors-ptest \
     python3-appdirs-ptest \
-    python3-backports-functools-lru-cache-ptest \
     python3-bcrypt-ptest \
     python3-betamax-ptest \
     python3-blinker-ptest \