ci: remove usage of untrusted bpfcc-tools

We've migrated this job to Ubuntu 23.04, which
ships with newer versions of the tools:
https://packages.ubuntu.com/lunar/bpfcc-tools.

ci/test/01_base_install.sh

@@ -21,14 +21,6 @@ if [[ $CI_IMAGE_NAME_TAG == *centos* ]]; then
   ${CI_RETRY_EXE} bash -c "dnf -y install epel-release"
   ${CI_RETRY_EXE} bash -c "dnf -y --allowerasing install $CI_BASE_PACKAGES $PACKAGES"
 elif [ "$CI_USE_APT_INSTALL" != "no" ]; then
-  if [[ "${ADD_UNTRUSTED_BPFCC_PPA}" == "true" ]]; then
-    # Ubuntu 22.04 LTS and Debian 11 both have an outdated bpfcc-tools packages.
-    # The iovisor PPA is outdated as well. The next Ubuntu and Debian releases will contain updated
-    # packages. Meanwhile, use an untrusted PPA to install an up-to-date version of the bpfcc-tools
-    # package.
-    # TODO: drop this once we can use newer images in GCE
-    add-apt-repository ppa:hadret/bpfcc
-  fi
   if [[ -n "${APPEND_APT_SOURCES_LIST}" ]]; then
     echo "${APPEND_APT_SOURCES_LIST}" >> /etc/apt/sources.list
   fi