GHA: use more ninja, build examples in the last step, and more

- linux: bump up test parallelism for valgrind tests to `-j4`
  (from `-j2`). (EXPERIMENTAL)
- linux: drop `apt-get update` for the default architecture on the GHA
  native runner. It makes prereq install steps complete faster.
  The runner image gets weekly updates, and that should be enough to
  guarantee fresh packages in most cases:
  https://github.com/actions/runner-images/commits/main/images/ubuntu/Ubuntu2204-Readme.md
- aws-lc: use ninja with cmake.
- aws-lc: build examples with cmake.
- aws-lc: drop `apt update`.
- aws-lc, wolfssl, linux32, http3-linux: move building examples to
  the last step.
  Follow-up to 45202cbba4 #14906
- windows: formatting.

Closes #14992

.github/workflows/http3-linux.yml

@@ -160,8 +160,6 @@ jobs:
       - name: install build prerequisites
         if: steps.settings.outputs.needs-build == 'true'
         run: |
-          sudo rm -f /etc/apt/sources.list.d/microsoft-prod.list
-          sudo apt-get update
           sudo apt-get install libtool autoconf automake pkgconf stunnel4 \
             libpsl-dev libbrotli-dev libzstd-dev zlib1g-dev libev-dev libc-ares-dev \
             nettle-dev libp11-kit-dev libtspi-dev libunistring-dev guile-2.2-dev libtasn1-bin \
@@ -296,8 +294,6 @@ jobs:
 
     steps:
       - run: |
-          sudo rm -f /etc/apt/sources.list.d/microsoft-prod.list
-          sudo apt-get update
           sudo apt-get install libtool autoconf automake pkgconf stunnel4 \
             libpsl-dev libbrotli-dev libzstd-dev zlib1g-dev libev-dev libc-ares-dev \
             nettle-dev libp11-kit-dev libtspi-dev libunistring-dev guile-2.2-dev libtasn1-bin \
@@ -457,9 +453,6 @@ jobs:
       - run: make V=1
         name: 'make'
 
-      - run: make V=1 examples
-        name: 'make examples'
-
       - run: make V=1 -C tests
         name: 'make tests'
 
@@ -473,3 +466,6 @@ jobs:
         env:
           TFLAGS: "${{ matrix.build.tflags }}"
           CURL_CI: github
+
+      - run: make V=1 examples
+        name: 'make examples'