fix: ci: Fix Clang TSAN reports

Disabling dynamic tags ensures the Clang symbolizer creates a valid TSAN
report. For consistency, also add the option to gcc:tsan so they are
both on the same footing.

Closes #5149

Merge branch '5149-fix-tsan-flags' into 'main'

See merge request isc-projects/bind9!10185

.gitlab-ci.yml

@@ -1305,7 +1305,7 @@ gcc:tsan:
   variables:
     CC: gcc
     CFLAGS: "${CFLAGS_COMMON} -Wno-stringop-overread -ggdb -O2 -fsanitize=thread"
-    LDFLAGS: "-fsanitize=thread"
+    LDFLAGS: "-fsanitize=thread -Wl,--disable-new-dtags"
     EXTRA_CONFIGURE: "--with-libidn2 --enable-pthread-rwlock --without-jemalloc PKG_CONFIG_PATH=/opt/tsan/lib/pkgconfig"
   <<: *tsan_fedora_41_amd64_image
   <<: *build_job
@@ -1334,7 +1334,8 @@ clang:tsan:
   variables:
     CC: "${CLANG}"
     CFLAGS: "${CFLAGS_COMMON} -ggdb -O2 -fsanitize=thread"
-    LDFLAGS: "-fsanitize=thread"
+    # -Wl,--disable-new-dtags ensures that Clang creates valid TSAN reports
+    LDFLAGS: "-fsanitize=thread -Wl,--disable-new-dtags"
     EXTRA_CONFIGURE: "--with-libidn2 --enable-pthread-rwlock --without-jemalloc PKG_CONFIG_PATH=/opt/tsan/lib/pkgconfig"
 
 system:clang:tsan:

util/generate-tsan-stress-jobs.py

@@ -29,7 +29,6 @@ for tsan_job in "gcc:tsan", "clang:tsan":
         tsan_stress_test_job["needs"] = [
             {"pipeline": "$PARENT_PIPELINE_ID", "job": tsan_job}
         ]
-        del tsan_stress_test_job["only"]
 
         print(
             yaml.dump(