runtests: add options to set minimum number of tests, use them

To detect mistakes made in the runtests framework that reduce
the number of test runs. Before this patch it could go undetected with
a green CI.

The minimum thresholds will need light maintenance going forward (either
bumping them periodically, or adjust if some may fell below minimums for
justified reasons). We may also make minimums tighter or looser, or more
job-specific.

Latest number of test runs for each job can be seen at Test Clutch:
https://testclutch.curl.se/static/reports/feature-matrix.html

Also:
- GHA: set minimums.

Assisted-by: Dan Fandrich

Follow-up to f2a75a14dd
Follow-up to bb1391f943 #19510

Closes #19942

.github/workflows/macos.yml

@@ -44,6 +44,7 @@ permissions: {}
 
 env:
   CURL_CI: github
+  CURL_TEST_MIN: 1700
   MAKEFLAGS: -j 4
   LDFLAGS: -w  # suppress 'object file was built for newer macOS version than being linked' warnings
 
@@ -225,16 +226,20 @@ jobs:
             compiler: clang
             install: brotli zstd
             configure: --without-ssl --with-brotli --with-zstd
+            tflags: '--min=1450'
             xcode: ''  # default Xcode. Set it once to silence actionlint.
           - name: '!ssl !debug'
             compiler: gcc-13
             configure: --without-ssl
+            tflags: '--min=950'
           - name: '!ssl'
             compiler: clang
             configure: --enable-debug --without-ssl
+            tflags: '--min=1500'
           - name: '!ssl libssh2 AppleIDN'
             compiler: clang
             configure: --enable-debug --with-libssh2=/opt/homebrew/opt/libssh2 --without-ssl --with-apple-idn
+            tflags: '--min=1550'
           - name: 'OpenSSL libssh c-ares'
             compiler: clang
             install: libssh
@@ -246,8 +251,10 @@ jobs:
           - name: '!ssl c-ares'
             compiler: clang
             configure: --enable-debug --enable-ares --without-ssl
+            tflags: '--min=1500'
           - name: '!ssl HTTP-only'
             compiler: clang
+            tflags: '--min=950'
             configure: >-
               --enable-debug
               --disable-alt-svc --disable-dict --disable-file --disable-ftp --disable-gopher --disable-imap
@@ -277,7 +284,7 @@ jobs:
           - name: 'OpenSSL event-based'
             compiler: clang
             configure: --enable-debug --with-openssl=/opt/homebrew/opt/openssl
-            tflags: --test-event
+            tflags: '--test-event --min=1300'
           # cmake
           - name: 'OpenSSL gsasl rtmp AppleIDN SecTrust +examples'
             install: libnghttp3 libngtcp2 gsasl rtmpdump
@@ -328,18 +335,19 @@ jobs:
             compiler: clang
             install: rustls-ffi
             generate: -DENABLE_DEBUG=ON -DCURL_USE_RUSTLS=ON -DUSE_ECH=ON -DCURL_DISABLE_LDAP=ON
+            tflags: '--min=1650'
           - name: 'OpenSSL torture !FTP'
             compiler: clang
             install: libnghttp3
             install_steps: torture
             generate: -DENABLE_DEBUG=ON -DBUILD_SHARED_LIBS=OFF -DENABLE_THREADED_RESOLVER=OFF -DOPENSSL_ROOT_DIR=/opt/homebrew/opt/openssl -DUSE_OPENSSL_QUIC=ON
-            tflags: -t --shallow=25 !FTP
+            tflags: '-t --shallow=25 !FTP --min=1450'
           - name: 'OpenSSL torture FTP'
             compiler: clang
             install: libnghttp3
             install_steps: torture
             generate: -DENABLE_DEBUG=ON -DBUILD_SHARED_LIBS=OFF -DENABLE_THREADED_RESOLVER=OFF -DOPENSSL_ROOT_DIR=/opt/homebrew/opt/openssl -DUSE_OPENSSL_QUIC=ON
-            tflags: -t --shallow=20 FTP
+            tflags: '-t --shallow=20 FTP --min=260'
         exclude:
           # opt out jobs from combinations that have the compiler set manually
           - { compiler: llvm@18, build: { compiler: 'clang' } }