ci: broaden coverage-fanout source filter beyond lib/

The isSource predicate only matched lib/, but driver source also lives at
native/ (kernel bindings), thrift/ (Thrift defs), and the KERNEL_REV pin.
A merged PR that only bumped KERNEL_REV or edited native/ or thrift/ would
report srcChanged=false and never dispatch coverage-fanout, even though it
affects the Thrift/kernel backends — the same gap the "run on every change"
comments in this workflow already document. Include those roots.

Co-authored-by: Isaac
Signed-off-by: eric-wang-1990 <e.wang@databricks.com>

Author: eric-wang-1990

.github/workflows/trigger-integration-tests.yml

@@ -327,9 +327,13 @@ jobs:
               pull_number: context.payload.pull_request.number,
               per_page: 100,
             });
-            // The whole repo IS the driver. Count a merge as source-affecting when it changes a file under lib/.
-            // Docs/CI/test-only merges do not warrant a full multi-language fan-out.
-            const isSource = (f) => f.startsWith('lib/');
+            // The whole repo IS the driver. Count a merge as source-affecting when it changes driver
+            // source: lib/ (JS/TS), native/ (kernel bindings), thrift/ (Thrift defs), or the KERNEL_REV
+            // pin. Docs/CI/test-only merges do not warrant a full multi-language fan-out. (Matches the
+            // source roots called out in the "run on every change" comments above — a merge that only
+            // bumps KERNEL_REV or edits native/ or thrift/ still affects the Thrift/kernel backends.)
+            const isSource = (f) =>
+              f.startsWith('lib/') || f.startsWith('native/') || f.startsWith('thrift/') || f === 'KERNEL_REV';
             const srcChanged = files.some((f) => isSource(f.filename));
             console.log(`driver source changed: ${srcChanged}`);
             core.setOutput('source', srcChanged.toString());