yaml-cpp: add run_tests.sh (google#13591)

Adds `run_tests.sh` to the expat project.

`run_tests.sh` is used as part of Chronos with cached builds:
https://github.com/google/oss-fuzz/tree/master/infra/experimental/chronos#check-tests

Output of ./infra/experimental/chronos/check_tests.sh yaml-cpp c++:
```
Running tests...
Test project /src/yaml-cpp/build
    Start 1: yaml-cpp::test
1/1 Test #1: yaml-cpp::test ...................   Passed    1.32 sec

100% tests passed, 0 tests failed out of 1

Total Test time (real) =   1.32 sec
```

Author: vitaliset

projects/yaml-cpp/Dockerfile

@@ -24,6 +24,6 @@ RUN apt-get update && \
 RUN git clone --depth 1 https://github.com/jbeder/yaml-cpp.git $SRC/yaml-cpp/
 RUN git clone --depth 1 https://github.com/initializedd/yaml-cpp-fuzzer.git $SRC/yaml-cpp-fuzzer/
 
-COPY build.sh $SRC/
+COPY build.sh run_tests.sh $SRC/
 WORKDIR $SRC/yaml-cpp/
 

projects/yaml-cpp/build.sh

@@ -19,7 +19,7 @@
 mkdir build
 cd build
 
-cmake -DCMAKE_BUILD_TYPE=Release ..
+cmake -DCMAKE_BUILD_TYPE=Release -DYAML_CPP_BUILD_TESTS=ON ..
 make -j4
 
 cp $SRC/yaml-cpp-fuzzer/*.dict $OUT/

projects/yaml-cpp/run_tests.sh

@@ -0,0 +1,18 @@
+#!/bin/bash -eu
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+################################################################################
+
+cd build
+make test