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/git.cue

@@ -0,0 +1,30 @@
+package dagger
+
+// Push a directory to a git remote
+#GitPush: {
+	@dagger(notimplemented)
+	$dagger: task: _name: "GitPush"
+
+	input:  #FS
+	remote: string
+	ref:    string
+}
+
+// Pull a directory from a git remote
+// Warning: do NOT embed credentials in the remote url as this will expose them in logs. 
+// By using username and password Dagger will handle this for you in a secure manner.
+#GitPull: {
+	$dagger: task: _name: "GitPull"
+	remote:     string
+	ref:        string
+	keepGitDir: true | *false
+	auth?:      {
+		username: string
+		password: #Secret // can be password or personal access token
+	} | {
+		authToken: #Secret
+	} | {
+		authHeader: #Secret
+	}
+	output: #FS
+}