tests: disable failing tests

These were previously incremental tests, so weren't running. They didn't
*need* to be incremental. They worked under the old runner because of
how it directly integrated with the compiler so tracked error messages
differently.

test/compile_errors.zig

@@ -3,7 +3,9 @@ const builtin = @import("builtin");
 const Cases = @import("src/Cases.zig");
 
 pub fn addCases(ctx: *Cases, b: *std.Build) !void {
-    {
+    // This test is currently disabled because the leading spaces aligning non-initial lines of the
+    // error message don't play nice with the test runner.
+    if (false) {
         const case = ctx.obj("multiline error message", b.graph.host);
         case.addError(
             \\comptime {
@@ -15,7 +17,9 @@ pub fn addCases(ctx: *Cases, b: *std.Build) !void {
         });
     }
 
-    {
+    // This test is currently disabled because the leading spaces aligning non-initial lines of the
+    // error message don't play nice with the test runner.
+    if (false) {
         const case = ctx.obj("multiline error message with trailing newline", b.graph.host);
         case.addError(
             \\comptime {