Update Dockerfiles and images for Spack v0.18.0 (#30216)

This PR updates the list of images we build nightly, deprecating 
Ubuntu 16.04 and CentOS 8 and adding Ubuntu 20.04, Ubuntu 22.04
and CentOS Stream. It also removes a lot of duplication by generating
the Dockerfiles during the CI workflow and uploading them as artifacts
for later inspection or reuse.

lib/spack/spack/container/images.json

@@ -12,11 +12,19 @@
       },
       "os_package_manager": "yum_amazon"
     },
-    "centos:8": {
+    "centos:stream": {
       "bootstrap": {
-        "template": "container/centos_8.dockerfile"
+        "template": "container/centos_stream.dockerfile",
+        "image": "quay.io/centos/centos:stream"
       },
-      "os_package_manager": "yum"
+      "os_package_manager": "yum",
+      "build": "spack/centos-stream",
+      "final": {
+        "image": "quay.io/centos/centos:stream"
+      },
+      "build_tags": {
+        "develop": "latest"
+      }
     },
     "centos:7": {
       "bootstrap": {
@@ -51,10 +59,24 @@
       },
       "os_package_manager": "apt"
     },
+    "ubuntu:22.04": {
+      "bootstrap": {
+        "template": "container/ubuntu_2204.dockerfile"
+      },
+      "os_package_manager": "apt",
+      "build": "spack/ubuntu-jammy",
+      "build_tags": {
+        "develop": "latest"
+      }
+    },
     "ubuntu:20.04": {
       "bootstrap": {
         "template": "container/ubuntu_2004.dockerfile"
       },
+      "build": "spack/ubuntu-focal",
+      "build_tags": {
+        "develop": "latest"
+      },
       "os_package_manager": "apt"
     },
     "ubuntu:18.04": {
@@ -66,16 +88,6 @@
       "build_tags": {
         "develop": "latest"
       }
-    },
-    "ubuntu:16.04": {
-      "bootstrap": {
-        "template": "container/ubuntu_1604.dockerfile"
-      },
-      "os_package_manager": "apt",
-      "build": "spack/ubuntu-xenial",
-      "build_tags": {
-        "develop": "latest"
-      }
     }
   },
   "os_package_managers": {

lib/spack/spack/container/images.py

@@ -129,5 +129,6 @@ def checkout_command(url, ref, enforce_sha, verify):
     if enforce_sha or verify:
         ref = _verify_ref(url, ref, enforce_sha)
 
-    command = 'git clone {0} . && git checkout {1} '.format(url, ref)
+    command = ('git clone {0} . && git fetch origin {1}:container_branch &&'
+               ' git checkout container_branch ').format(url, ref)
     return command