Match callers and callees when root is not the repo root

When running codeql test run, the root of the database is not the root
of the original repo (the directory containing .github and .git)
therefore calls to reusable workflows are not correctly matched.

Author: Alvaro Muñoz

ql/lib/codeql/actions/dataflow/internal/DataFlowPrivate.qll

@@ -86,7 +86,7 @@ class DataFlowCall instanceof Cfg::Node {
   int totalorder() { none() }
 
   /** Gets the location of this call. */
-  Location getLocation() { result = this.getLocation() }
+  Location getLocation() { result = this.(Cfg::Node).getLocation() }
 }
 
 /**
@@ -97,7 +97,17 @@ class DataFlowCallable instanceof Cfg::CfgScope {
 
   string getName() {
     if this instanceof ReusableWorkflow
-    then result = this.(ReusableWorkflow).getLocation().getFile().getRelativePath()
+    then
+      result =
+        this.(ReusableWorkflow)
+            .getLocation()
+            .getFile()
+            .getRelativePath()
+            .suffix(this.(ReusableWorkflow)
+                    .getLocation()
+                    .getFile()
+                    .getRelativePath()
+                    .indexOf("/.github/workflows") + 1)
     else
       if this instanceof CompositeAction
       then
@@ -118,7 +128,7 @@ class DataFlowCallable instanceof Cfg::CfgScope {
   int totalorder() { none() }
 
   /** Gets the location of this callable. */
-  Location getLocation() { result = this.getLocation() }
+  Location getLocation() { result = this.(Cfg::CfgScope).getLocation() }
 }
 
 newtype TReturnKind = TNormalReturn()
@@ -380,8 +390,8 @@ predicate storeStep(Node node1, ContentSet c, Node node2) {
   fieldStoreStep(node1, node2, c) or
   madStoreStep(node1, node2, c) or
   envToOutputStoreStep(node1, node2, c) or
-  artifactToOutputStoreStep(node1, node2, c) or
   envToEnvStoreStep(node1, node2, c) or
+  artifactToOutputStoreStep(node1, node2, c) or
   artifactToEnvStoreStep(node1, node2, c)
 }