bci2: Add buildArgs argument

The `buildArgs` argument to `buildContainerImage2` accepts a list of
arguments that will be passed as `--build-arg` values to the `buildah
build` command.  For example,

```groovy
buildContainerImage2(buildArgs: ['FOO=bar'])
```

Would result in a command like

```sh
buildah build --build-arg FOO=bar ...
```

vars/buildContainerImage2.groovy

@@ -9,6 +9,8 @@ def call(args) {
     def schedule = args?.schedule
     def defaultBranch = args?.defaultBranch
     def pi = args?.pi
+    def resources = args?.resources
+    def buildArgs = args?.buildArgs
 
     properties([
         pipelineTriggers([cron(schedule ?: 'H H H * *')])
@@ -32,9 +34,6 @@ def call(args) {
     if (defaultBranch == null) {
         defaultBranch = 'main'
     }
-    if (pi == null) {
-        pi = true
-    }
     def repo = "${registry}/${project}/${name}"
     def full_name = "${repo}:${tag}"
 
@@ -48,14 +47,15 @@ def call(args) {
                     full_name: full_name,
                     registry: registry,
                     arch: arch,
-                    pi: pi,
+                    resources: resources,
+                    buildArgs: buildArgs,
                 )
             }
         }
     }
     parallel stages
 
-    runInPod(pi: false) {
+    runInPod {
         container('buildah') {
             withBuildahCreds(registry) {
                 if (archlist.size() > 1) {
@@ -96,14 +96,19 @@ def buildStage(args) {
     def full_name = args.full_name
     def registry = args.registry
     def arch = args.arch
-    def pi = args.pi
+    def resources = args?.resources
+    def buildArgs = args?.buildArgs ?: []
 
-    runInPod(arch: arch, pi: pi) {
+    def build_command = "buildah build -t '${full_name}'"
+    buildArgs.each { build_command += " --build-arg '${it}'" }
+    build_command += ' .'
+
+    runInPod(arch: arch, resources: resources) {
         checkout scm
 
         container('buildah') {
             withBuildahCreds(registry) {
-                sh "buildah build -t '${full_name}' ."
+                sh build_command
                 sh "buildah push '${full_name}' oci-archive:\${PWD}/${escapeImageName(name)}-${arch}.tar:${full_name}"
                 stash name: arch, includes: "${escapeImageName(name)}-*.tar"
             }
@@ -111,23 +116,24 @@ def buildStage(args) {
     }
 }
 
+def runInPod(block) {
+    runInPod(null, block)
+}
+
 def runInPod(args, block) {
     def arch = args?.arch
-    def pi = args?.pi
-    if (pi == null) {
-        pi = true
-    }
+    def resources = args?.resources
 
     def podTemplateYaml = libraryResource('podTemplate2.yaml')
-    if (pi) {
+    if (resources) {
         def tmpl = readYaml(text: podTemplateYaml)
-        def tolerations = tmpl['spec']['tolerations'] ?: []
-        tolerations.push([
-            key: 'du5t1n.me/machine',
-            value: 'raspberrypi',
-            effect: 'NoExecute',
-        ])
-        tmpl['spec']['tolerations'] = tolerations
+        tmpl.spec.containers.each { c ->
+            c.resources = c.resources ?: [:]
+            c.resources.putAll([
+                requests: (c.resources.requests ?: [:]) + resources,
+                limits: (c.resources.limits ?: [:]) + resources,
+            ])
+        }
         podTemplateYaml = writeYaml(data: tmpl, returnText: true)
     }
     podTemplate(