.travis.yml restored focal version

.travis.yml

@@ -1,17 +1,16 @@
 os: linux
-dist: jammy
+dist: focal
 language: perl
 perl:
-- 5.22.0
+- 5.30.0
 before_install:
 - sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9
-- sudo add-apt-repository 'deb https://cloud.r-project.org/bin/linux/ubuntu jammy-cran40/'
+- sudo add-apt-repository 'deb https://cloud.r-project.org/bin/linux/ubuntu focal-cran40/'
 - sudo apt update
 - sudo apt install -y libssl-dev libcurl4-openssl-dev curl build-essential bc make
   g++ r-base r-base-dev python2.7 python2.7-dev
 - cpanm --sudo -v --installdeps --notest --cpanfile cpanfile .
 before_script:
-- sudo apt autoremove
 - sudo make install
 script:
 - make test