[Test] Fix reference/cat/allocation/line_8 test failure
[Test] Fix reference/cat/allocation/line_8 test failure

In this test, 260b is replaced by the regexp \d+b
but the test sometimes produces results like 1.1kb
so this commit adapts the regexp to match values
with decimals

closes #26685

vroyer/elassandra,strapdata/elassandra,vroyer/elasticassandra,vroyer/elasticassandra,vroyer/elassandra,vroyer/elasticassandra,strapdata/elassandra,strapdata/elassandra,strapdata/elassandra,vroyer/elassandra,strapdata/elassandra