fix: switch babel-plugin-macros to a peer dependency (again) (#89)

## PR Checklist

- [x] Addresses an existing open issue: fixes #88
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/dmnd/dedent/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/dmnd/dedent/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Re-applies #60 per the issue.

knip.jsonc

@@ -1,6 +1,7 @@
 {
 	"$schema": "https://unpkg.com/knip@latest/schema.json",
 	"entry": ["src/index.ts!"],
+	"ignoreDependencies": ["babel-plugin-macros"],
 	"ignoreExportsUsedInFile": { "interface": true, "type": true },
 	"project": ["src/**/*.ts!"]
 }

package.json

@@ -63,9 +63,6 @@
 	"lint-staged": {
 		"*": "prettier --ignore-unknown --write"
 	},
-	"dependencies": {
-		"babel-plugin-macros": "^3.1.0"
-	},
 	"devDependencies": {
 		"@babel/cli": "^7.21.5",
 		"@babel/preset-env": "^7.23.3",
@@ -110,6 +107,14 @@
 		"typescript": "^5.2.2",
 		"yaml-eslint-parser": "^1.2.2"
 	},
+	"peerDependencies": {
+		"babel-plugin-macros": "^3.1.0"
+	},
+	"peerDependenciesMeta": {
+		"babel-plugin-macros": {
+			"optional": true
+		}
+	},
 	"packageManager": "pnpm@8.7.0",
 	"engines": {
 		"node": ">=18"