libcue: add run_tests.sh (google#13682)

`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

`infra/experimental/chronos/check_tests.sh libcue c`
```
Running tests...                                                                                 
Test project /work                                                                               
    Start 1: standard_cue_test                                                                   
1/6 Test #1: standard_cue_test ................   Passed    0.01 sec                             
    Start 2: single_file_idx_00_test                                                             
2/6 Test #2: single_file_idx_00_test ..........   Passed    0.01 sec                             
    Start 3: multiple_files_test                                                                 
3/6 Test #3: multiple_files_test ..............   Passed    0.01 sec                             
    Start 4: noncompliant_test                                                                                                                                                                     
4/6 Test #4: noncompliant_test ................   Passed    0.01 sec                             
    Start 5: issue10_test                                                                        
5/6 Test #5: issue10_test .....................   Passed    0.01 sec       
    Start 6: 99_tracks_test                                                                      
6/6 Test #6: 99_tracks_test ...................   Passed    0.01 sec                             
                                                                                                 
100% tests passed, 0 tests failed out of 6                                                       
                                                                                                 
Total Test time (real) =   0.06 sec                                                              
--------------------------------------------------------                                         
Total time taken to replay tests: 1
```

Signed-off-by: Adam Korczynski <adam@adalogics.com>

Author: AdamKorcz

projects/libcue/Dockerfile

@@ -20,4 +20,4 @@ RUN apt-get update && apt-get install -y make autoconf automake libtool bison fl
 RUN git clone --depth 1 https://github.com/lipnitsk/libcue.git libcue
 
 WORKDIR libcue
-COPY build.sh $SRC/
+COPY run_tests.sh build.sh $SRC/

projects/libcue/run_tests.sh

@@ -0,0 +1,18 @@
+#!/bin/bash -eux
+# 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 $WORK
+make test