remove jq dependency in the tests, port to GNU sed

This avoids spreading the jq dependency to more places, like:

https://gitlab.com/eighthave/ansible-role-install-fdroidserver-dependencies/-/jobs/5559798360

And is helpful when porting to non-Debian platforms.

.gitlab-ci.yml

@@ -19,7 +19,7 @@ buildserver run-tests:
   image: registry.gitlab.com/fdroid/fdroidserver:buildserver
   script:
     - apt-get update
-    - apt-get install gnupg-agent jq python3-babel python3-clint
+    - apt-get install gnupg-agent python3-babel python3-clint
     - ./tests/run-tests
     # make sure that translations do not cause stacktraces
     - cd $CI_PROJECT_DIR/locale
@@ -98,7 +98,6 @@ debian_testing:
         git
         gnupg
         ipfs-cid
-        jq
         python3-defusedxml
         python3-setuptools
         sdkmanager
@@ -123,7 +122,7 @@ ubuntu_lts_ppa:
     - echo "deb http://ppa.launchpad.net/fdroid/fdroidserver/ubuntu $RELEASE main" >> /etc/apt/sources.list
     - apt-get update
     - apt-get dist-upgrade
-    - apt-get install --install-recommends dexdump fdroidserver git jq python3-setuptools sdkmanager
+    - apt-get install --install-recommends dexdump fdroidserver git python3-setuptools sdkmanager
 
     # Test things work with a default branch other than 'master'
     - git config --global init.defaultBranch thisisnotmasterormain
@@ -139,7 +138,7 @@ ubuntu_jammy_pip:
   image: ubuntu:jammy
   <<: *apt-template
   script:
-    - apt-get install git default-jdk-headless jq python3-pip python3-venv rsync
+    - apt-get install git default-jdk-headless python3-pip python3-venv rsync
 
     # setup venv to act as release build machine
     - python3 -m venv sdist-env
@@ -279,7 +278,6 @@ fedora_latest:
                      git
                      gnupg
                      java-17-openjdk-devel
-                     jq
                      openssl
                      python3
                      python3-babel