update action to dagger 0.2

- Remove AGE key setup
- Update README to use `dagger do`
- Update tests to dagger 0.2

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

test/cue.mod/pkg/dagger.io/dagger/image.cue

@@ -0,0 +1,190 @@
+package dagger
+
+import (
+	"list"
+)
+
+// Upload a container image to a remote repository
+#Push: {
+	$dagger: task: _name: "Push"
+
+	// Target repository address
+	dest: #Ref
+
+	// Filesystem contents to push
+	input: #FS
+
+	// Container image config
+	config: #ImageConfig
+
+	// Authentication
+	auth?: {
+		username: string
+		secret:   #Secret
+	}
+
+	// Complete ref of the pushed image, including digest
+	result: #Ref
+}
+
+// A ref is an address for a remote container image
+//
+// Examples:
+//   - "index.docker.io/dagger"
+//   - "dagger"
+//   - "index.docker.io/dagger:latest"
+//   - "index.docker.io/dagger:latest@sha256:a89cb097693dd354de598d279c304a1c73ee550fbfff6d9ee515568e0c749cfe"
+#Ref: string
+
+// Container image config. See [OCI](https://www.opencontainers.org/).
+#ImageConfig: {
+	user?: string
+	expose?: [string]: {}
+	env?: [string]: string
+	entrypoint?: [...string]
+	cmd?: [...string]
+	volume?: [string]: {}
+	workdir?: string
+	label?: [string]: string
+	stopsignal?:  string
+	healthcheck?: #HealthCheck
+	argsescaped?: bool
+	onbuild?: [...string]
+	stoptimeout?: int
+	shell?: [...string]
+}
+
+#HealthCheck: {
+	test?: [...string]
+	interval?:    int
+	timeout?:     int
+	startperiod?: int
+	retries?:     int
+}
+
+// Download a container image from a remote repository
+#Pull: {
+	$dagger: task: _name: "Pull"
+
+	// Repository source ref
+	source: #Ref
+
+	// Authentication
+	auth?: {
+		username: string
+		secret:   #Secret
+	}
+
+	// Root filesystem of downloaded image
+	output: #FS
+
+	// Image digest
+	digest: string
+
+	// Downloaded container image config
+	config: #ImageConfig
+}
+
+// Build a container image using a Dockerfile
+#Dockerfile: {
+	$dagger: task: _name: "Dockerfile"
+
+	// Source directory to build
+	source: #FS
+
+	dockerfile: *{
+		path: string | *"Dockerfile"
+	} | {
+		contents: string
+	}
+
+	// Authentication
+	auth: [registry=string]: {
+		username: string
+		secret:   #Secret
+	}
+
+	platforms?: [...string]
+	target?: string
+	buildArg?: [string]: string
+	label?: [string]:    string
+	hosts?: [string]:    string
+
+	// Root filesystem produced
+	output: #FS
+
+	// Container image config produced
+	config: #ImageConfig
+}
+
+// Change image config
+#Set: {
+	// The source image config
+	input: #ImageConfig
+
+	// The config to merge
+	config: #ImageConfig
+
+	// Resulting config
+	output: #ImageConfig & {
+		let structs = ["env", "label", "volume", "expose"]
+		let lists = ["onbuild"]
+
+		// doesn't exist in config, copy away
+		for field, value in input if config[field] == _|_ {
+			"\(field)": value
+		}
+
+		// only exists in config, just copy as is
+		for field, value in config if input[field] == _|_ {
+			"\(field)": value
+		}
+
+		// these should exist in both places
+		for field, value in config if input[field] != _|_ {
+			"\(field)": {
+				// handle structs that need merging
+				if list.Contains(structs, field) {
+					_#mergeStructs & {
+						#a: input[field]
+						#b: config[field]
+					}
+				}
+
+				// handle lists that need concatenation
+				if list.Contains(lists, field) {
+					list.Concat([
+						input[field],
+						config[field],
+					])
+				}
+
+				// replace anything else
+				if !list.Contains(structs+lists, field) {
+					value
+				}
+			}
+		}
+	}
+}
+
+// Merge two structs by overwriting or adding values
+_#mergeStructs: {
+	// Struct with defaults
+	#a: [string]: _
+
+	// Struct with overrides
+	#b: [string]: _
+	{
+		// FIXME: we need exists() in if because this matches any kind of error (cue-lang/cue#943)
+		// add anything not in b
+		for field, value in #a if #b[field] == _|_ {
+			"\(field)": value
+		}
+
+		// safely add all of b
+		for field, value in #b {
+			"\(field)": value
+		}
+	}
+}