Move python2.7 ecosystem to security-support-ended.11

python2.7, cpython, jython, pypy and python-stdlib-extensions have been EOL'ed in bullseye. The main reason for keeping in python2.7 in bullseye was the chromium's build system at the initial release time. However, the current version of chromium has moved away from python2.7 since then.

Moving these packages from security-support-limited.11 to security-support-ended.deb11 should be make it more clear (explicit) their security support situation.