GHA: run random curl command lines for N seconds in CI

In the memory and address sanitizer builds.

Verify that nothing unexpected happens.

Starting out with 60 second runs.

The script does not set any seed so it runs with a new random every
time, meaning that if it fails in a single CI run it might not fail in a
subsequent one: but it should still show the full command that failed to
enable us to reproduce it locally. We can work on improving the seed
situation later if this script turns useful.

Closes #16884

.github/workflows/linux.yml

@@ -228,7 +228,7 @@ jobs:
 
           - name: address-sanitizer
             install_packages: zlib1g-dev libssh2-1-dev clang libssl-dev libubsan1 libasan8 libtsan2
-            install_steps: pytest
+            install_steps: pytest randcurl
             configure: >-
               CC=clang
               CFLAGS="-fsanitize=address,undefined,signed-integer-overflow -fno-sanitize-recover=undefined,integer -Wformat -Werror=format-security -Werror=array-bounds -g"
@@ -247,6 +247,7 @@ jobs:
 
           - name: memory-sanitizer
             install_packages: clang
+            install_steps: randcurl
             configure: >-
               CC=clang
               CFLAGS="-fsanitize=memory -Wformat -Werror=format-security -Werror=array-bounds -g"
@@ -697,6 +698,13 @@ jobs:
             make -C bld V=1 pytest-ci
           fi
 
+      - name: 'randcurl'
+        if: ${{ contains(matrix.build.install_steps, 'randcurl') }}
+        run: |
+          mkdir run
+          cd run
+          ../.github/scripts/randcurl.pl 60 ../bld/src/curl
+
       - name: 'build examples'
         if: ${{ matrix.build.make-custom-target != 'tidy' }}
         run: |