ci: Bring in various improvements from uefi-rs

* Update the `on` to run on pushes to `main`, on pull requests to
  `main`, and once a week (arbitrarily on Thursday) to catch bitrot
* Update to actions/checkout v3
* Drop use of unmaintained actions-rs/toolchain
* Add caching with Swatinem/rust-cache

Author: nicholasbishop

.github/workflows/rust.yml

@@ -1,21 +1,24 @@
 name: Rust
 
-on: [push]
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+  schedule:
+    - cron: '0 0 * * 4'
 
 jobs:
   check:
     name: Check
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v1
+        uses: actions/checkout@v3
 
-      - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: stable
-          override: true
+      - uses: Swatinem/rust-cache@v2
 
       - name: Run cargo check
         uses: actions-rs/cargo@v1
@@ -27,43 +30,28 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v1
+        uses: actions/checkout@v3
 
-      - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: stable
-          override: true
+      - uses: Swatinem/rust-cache@v2
 
       - name: Run cargo test
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
+        run: cargo test
 
   lints:
     name: Lints
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v1
+        uses: actions/checkout@v3
 
-      - name: Install stable toolchain
-        uses: actions-rs/toolchain@v1
-        with:
-          profile: minimal
-          toolchain: stable
-          override: true
-          components: rustfmt, clippy
+      - uses: Swatinem/rust-cache@v2
 
       - name: Run cargo fmt
-        uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: --all -- --check
+        run: |
+          rustup component add rustfmt
+          cargo fmt --all -- --check
 
       - name: Run cargo clippy
-        uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: -- -D warnings
+        run: |
+          rustup component add clippy
+          cargo clippy -- -D warnings