Time out workflows after 45 minutes

GitHub's default timeout is 6 hours. Recently some of my GitHub Actions
jobs have started randomly stalling for that long, which is inconvenient
because it ties up a chunk of my runner quota. It apepars to be very
rare for a job to recover after stalling. It's better to time out
quicker and retry on a different runner.

Author: dtolnay

.github/workflows/ci.yml

@@ -15,6 +15,7 @@ jobs:
   test:
     name: Check answers
     runs-on: ubuntu-latest
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@nightly
@@ -32,6 +33,7 @@ jobs:
       fail-fast: false
       matrix:
         rust: [beta, stable]
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@master
@@ -43,6 +45,7 @@ jobs:
     name: Clippy
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request'
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@clippy
@@ -52,6 +55,7 @@ jobs:
     name: Outdated
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request'
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/install@cargo-outdated