feat: unified CI jobs into one ci.yml (#1608)

## PR Checklist

- [x] Addresses an existing open issue: fixes #1099
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Comes with a nice overall reduction in line count too, despite the
addition of `createMultiWorkflowFile.ts`.

💖

Author: JoshuaKGoldberg

.github/workflows/build.yml

@@ -0,0 +1,77 @@
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm build
+      - run: node ./lib/index.js
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm build
+      - run: pnpm lint
+  lint_knip:
+    name: Lint Knip
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm lint:knip
+  lint_markdown:
+    name: Lint Markdown
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm lint:md
+  lint_packages:
+    name: Lint Packages
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm lint:packages
+  lint_spelling:
+    name: Lint Spelling
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm lint:spelling
+  prettier:
+    name: Prettier
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm format --list-different
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm run test --coverage
+      - uses: codecov/codecov-action@v3
+        with:
+          flags: unit
+  type_check:
+    name: Type Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/prepare
+      - run: pnpm tsc
+
+name: CI
+
+on:
+  pull_request: ~
+  push:
+    branches:
+      - main