chore: upgrade to edition 2021 (#3171)

.github/workflows/security-audit.yml

@@ -2,20 +2,28 @@ name: Security audit
 on:
   pull_request:
     paths:
-      - '**/Cargo.toml'
-      - '**/Cargo.lock'
+      - "**/Cargo.toml"
+      - "**/Cargo.lock"
   push:
     paths:
-      - '**/Cargo.toml'
-      - '**/Cargo.lock'
+      - "**/Cargo.toml"
+      - "**/Cargo.lock"
   schedule:
-    - cron: '0 0 * * *'
+    - cron: "0 0 * * *"
 jobs:
   security_audit:
     if: (github.event_name == 'schedule' && github.repository == 'starship/starship') || (github.event_name != 'schedule')
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2.3.5
-      - uses: actions-rs/audit-check@v1.2.0
+      - name: Setup | Checkout
+        uses: actions/checkout@v2.3.5
+      - name: Setup | Rust
+        uses: actions-rs/toolchain@v1.0.7
+        with:
+          toolchain: stable
+          override: true
+          profile: minimal
+      - name: Test | Security Audit
+        uses: actions-rs/audit-check@v1.2.0
         with:
           token: ${{ secrets.GITHUB_TOKEN }}

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "starship"
 version = "0.58.0"
-edition = "2018"
+edition = "2021"
 authors = ["Matan Kushner <hello@matchai.me>"]
 homepage = "https://starship.rs"
 documentation = "https://starship.rs/guide/"

starship_module_config_derive/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "starship_module_config_derive"
 version = "0.2.1"
-edition = "2018"
+edition = "2021"
 authors = ["Matan Kushner <hello@matchai.me>"]
 homepage = "https://starship.rs"
 documentation = "https://starship.rs/guide/"