Use Ubuntu 22.04 for the buildbox (#27497)

After moving the Connect to a separate Docker image #27175 we're able to use the latest ubuntu LTS on our build image. We're not using this image to produce any releases (only CI runs), so updating the image will have no effect on our releases.

build.assets/Dockerfile

@@ -10,7 +10,7 @@
 ## LIBFIDO2 ###################################################################
 
 # Build libfido2 separately for isolation, speed and flexibility.
-FROM buildpack-deps:20.04 AS libfido2
+FROM buildpack-deps:22.04 AS libfido2
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends cmake && \
@@ -62,7 +62,7 @@ RUN git clone --depth=1 https://github.com/Yubico/libfido2.git -b 1.13.0 && \
 
 ## LIBBPF #####################################################################
 
-FROM buildpack-deps:20.04 AS libbpf
+FROM buildpack-deps:22.04 AS libbpf
 
 # Install required dependencies
 RUN apt-get update -y --fix-missing && \
@@ -94,7 +94,7 @@ RUN mkdir -p /opt && cd /opt &&  \
 # 4. Fast, language-dependent dependencies
 # 5. Multi-stage layer copies
 
-FROM ubuntu:20.04 AS buildbox
+FROM ubuntu:22.04 AS buildbox
 
 COPY locale.gen /etc/locale.gen
 COPY profile /etc/profile
@@ -146,8 +146,6 @@ RUN apt-get -y update && \
         python3-setuptools \
         python3-wheel \
         pkg-config \
-        # Used during tag builds to build the RPM package of Connect.
-        rpm \
         softhsm2 \
         sudo \
         tree \
@@ -256,13 +254,6 @@ RUN mkdir -p helm-tarball && \
     curl -fsSL https://get.helm.sh/helm-v3.5.2-$(go env GOOS)-$(go env GOARCH).tar.gz | tar -C helm-tarball -xz && \
     cp helm-tarball/$(go env GOOS)-$(go env GOARCH)/helm /bin/ && \
     rm -r helm-tarball*
-# TODO(hugoShaka): remove this backward compatible hack with teleportv13 buildbox
-RUN helm plugin install https://github.com/quintush/helm-unittest --version 0.2.11 && \
-    mkdir -p /home/ci/.local/share/helm && \
-    cp -r /root/.local/share/helm/plugins /home/ci/.local/share/helm/plugins-new && \
-    chown -R ci /home/ci/.local/share/helm && \
-    helm plugin uninstall unittest && \
-    HELM_PLUGINS=/home/ci/.local/share/helm/plugins-new helm plugin list
 RUN helm plugin install https://github.com/vbehar/helm3-unittest && \
     mkdir -p /home/ci/.local/share/helm && \
     cp -r /root/.local/share/helm/plugins /home/ci/.local/share/helm && \

build.assets/Makefile

@@ -7,8 +7,7 @@ endif
 HOSTNAME=buildbox
 SRCDIR=/go/src/github.com/gravitational/teleport
 GOMODCACHE ?= /tmp/gomodcache
-# TODO(hugoShaka) remove HELM_PLUGINS with teleport13 buildbox
-DOCKERFLAGS := --rm=true -v "$$(pwd)/../":$(SRCDIR) -v /tmp:/tmp -w $(SRCDIR) -h $(HOSTNAME) -e GOMODCACHE=$(GOMODCACHE) -e HELM_PLUGINS=/home/ci/.local/share/helm/plugins-new
+DOCKERFLAGS := --rm=true -v "$$(pwd)/../":$(SRCDIR) -v /tmp:/tmp -w $(SRCDIR) -h $(HOSTNAME) -e GOMODCACHE=$(GOMODCACHE)
 
 ADDFLAGS ?=
 BATSFLAGS :=