[bazel] Disable backend keep alive (#110259) (#110307)

Signed-off-by: Tyler Smalley <tyler.smalley@elastic.co>
Co-authored-by: Tiago Costa <tiagoffcc@hotmail.com>

Co-authored-by: Tyler Smalley <tyler.smalley@elastic.co>
Co-authored-by: Tiago Costa <tiagoffcc@hotmail.com>

src/dev/ci_setup/.bazelrc-ci

@@ -12,5 +12,8 @@ build --bes_backend=grpcs://cloud.buildbuddy.io
 build --remote_cache=grpcs://cloud.buildbuddy.io
 build --remote_timeout=3600
 
+## Avoid to keep connections to build event backend connections alive across builds
+build --keep_backend_build_event_connections_alive=false
+
 ## Metadata settings
 build --build_metadata=ROLE=CI