tests: parametrize package name in embedded interpreter test

It's different in collection, and therefore rpm query fails.

tests/python-embedded-interpreter/main.fmf

@@ -6,9 +6,13 @@ adjust:
   # Common requirements when LLVM is not SCL-ized
   - require+:
       - lldb
+    environment+:
+      LLDB_PACKAGE: lldb
     when: "collection is not defined"
 
   # Requirements for SCL-ized LLVM
   - require+:
       - llvm-toolset-13.0-lldb
+    environment+:
+      LLDB_PACKAGE: llvm-toolset-13.0-lldb
     when: "collection == llvm-toolset-13.0"

tests/python-embedded-interpreter/test.sh

@@ -1,7 +1,7 @@
 #!/bin/sh -eux
 
 # Verify the formal side of things, lldb should really depend on its Python bits.
-rpm -q --requires lldb | grep python3-lldb
+rpm -q --requires "$LLDB_PACKAGE" | grep python3-lldb
 
 # Then verify things actually works.
 g++ -g test.cpp