[Test] Fix CLI tests due to migration from -Xuse-fir to -Xuse-k2 flag

compiler/testData/cli/js/fir.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/fir.kt
--Xuse-fir
+-Xuse-k2
 -output
 $TEMP_DIR$

compiler/testData/cli/jvm/pluginWithK2Error.args

@@ -7,4 +7,4 @@ plugin\:org.jetbrains.kotlin.android\:package=com.myapp
 plugin\:org.jetbrains.kotlin.android\:variant=main;$TESTDATA_DIR$/androidPlugin/res
 $TESTDATA_DIR$/pluginSimple.kt
 $TESTDATA_DIR$/androidPlugin
--Xuse-fir
+-Xuse-k2

compiler/testData/cli/jvm/pluginWithK2Error.out

@@ -1,6 +1,6 @@
 warning: ATTENTION!
- This build uses in-dev FIR:
-  -Xuse-fir
+ This build uses experimental K2 compiler:
+  -Xuse-k2
 error: compiler plugins are enabled with K2 compiler.
  K2 does not support plugins yet, so please remove -Xuse-k2 flag
 COMPILATION_ERROR

compiler/testData/cli/metadata/fir.args

@@ -1,4 +1,4 @@
 $TESTDATA_DIR$/fir.kt
--Xuse-fir
+-Xuse-k2
 -d
 $TEMP_DIR$