Disable man-db auto-update in GHAs (#248)

The dpkg man-db trigger is excessively slow on GHA runners, see e.g.:
- actions/runner-images#10977
- actions/runner#4030

We disable it so it does not fire at the end of an `apt-get install`. This can easily shave a minute or two off the execution time.

GUS-W-19995078

Author: dzuelke

.github/workflows/ci.yml

@@ -45,6 +45,12 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v5
+      # The dpkg man-db trigger is excessively slow on GHA runners, see e.g.:
+      # https://github.com/actions/runner-images/issues/10977
+      # https://github.com/actions/runner/issues/4030
+      # We disable it here so it does not fire at the end of the following apt-get install
+      - name: Disable man-db auto-update
+        run: sudo rm -f /var/lib/man-db/auto-update
       - name: Install musl-tools
         run: sudo apt-get install musl-tools --no-install-recommends
       - name: Update Rust toolchain
@@ -68,6 +74,12 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v5
+      # The dpkg man-db trigger is excessively slow on GHA runners, see e.g.:
+      # https://github.com/actions/runner-images/issues/10977
+      # https://github.com/actions/runner/issues/4030
+      # We disable it here so it does not fire at the end of the following apt-get install
+      - name: Disable man-db auto-update
+        run: sudo rm -f /var/lib/man-db/auto-update
       - name: Install musl-tools
         run: sudo apt-get install -y --no-install-recommends musl-tools
       - name: Update Rust toolchain