add cd for jenkins replacement scripts (#31355)

fix dirs
old-commit-hash: 6a463503a7a2d0c8f2d76c5633b9c9308b3c850c

selfdrive/car/tests/big_cars_test.sh

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+SCRIPT_DIR=$(dirname "$0")
+BASEDIR=$(realpath "$SCRIPT_DIR/../../../")
+cd $BASEDIR
+
 MAX_EXAMPLES=300
 INTERNAL_SEG_CNT=300
 FILEREADER_CACHE=1

selfdrive/test/scons_build_test.sh

@@ -1,5 +1,9 @@
 #!/bin/bash
 
+SCRIPT_DIR=$(dirname "$0")
+BASEDIR=$(realpath "$SCRIPT_DIR/../../")
+cd $BASEDIR
+
 # tests that our build system's dependencies are configured properly, 
 # needs a machine with lots of cores
 scons --clean