github: Don't use pip3 to install Python packages anymore

Currently, the runner images enable break-system-packages globally.
However, this workaround will be removed by the end of March.  So
we switch to installing these packages as intended via distro (the
alternative would be to use pipx, at least for tox).

.github/actions/default/action.yml

@@ -5,9 +5,6 @@ runs:
     - name: "Install Dependencies"
       run: ./scripts/test.sh deps
       shell: bash
-    - name: "Install Python Dependencies"
-      run: ./scripts/test.sh pydeps
-      shell: bash
     - name: "Build Dependencies"
       run: ./scripts/test.sh build-deps
       shell: bash

scripts/test.sh

@@ -306,8 +306,14 @@ all|alpine|codeql|coverage|sonarcloud|no-dbg)
 	DEPS="$DEPS libcurl4-gnutls-dev libsoup2.4-dev libunbound-dev libldns-dev
 		  libmysqlclient-dev libsqlite3-dev clearsilver-dev libfcgi-dev
 		  libldap2-dev libpcsclite-dev libpam0g-dev binutils-dev libnm-dev
-		  libgcrypt20-dev libjson-c-dev python3-pip libtspi-dev libsystemd-dev
+		  libgcrypt20-dev libjson-c-dev libtspi-dev libsystemd-dev
-		  libselinux1-dev libiptc-dev"
+		  libselinux1-dev libiptc-dev python3-build tox"
+	if [ "$ID" = "ubuntu" -a "$VERSION_ID" = "22.04" -a "$1" = "build-deps" ]; then
+		# python3-build is broken on 22.04 with venv (https://bugs.launchpad.net/ubuntu/+source/python-build/+bug/1992108)
+		# while installing python3-virtualenv should help, it doesn't. as even
+		# after uninstalling python3-venv, build prefers the latter
+		sudo python3 -m pip install --upgrade build
+	fi
 	if [ "$TEST" = "alpine" ]; then
 		# override the whole list for alpine
 		DEPS="git gmp-dev openldap-dev curl-dev ldns-dev unbound-dev libsoup-dev
@@ -324,7 +330,6 @@ all|alpine|codeql|coverage|sonarcloud|no-dbg)
 		# and no Clearsilver
 		CONFIG="$CONFIG --disable-fast --disable-manager --disable-medsrv"
 	fi
-	PYDEPS="build tox"
 	if test "$1" = "build-deps"; then
 		build_botan
 		build_wolfssl
@@ -491,10 +496,6 @@ deps)
 	esac
 	exit $?
 	;;
-pydeps)
-	test -z "$PYDEPS" || pip3 -q install --user $PYDEPS
-	exit $?
-	;;
 build-deps)
 	exit
 	;;