Update for Zig 0.11

[dadrian]

This updates build.zig to use the newer APIs, and changes ctregex.zig to build under 0.11.0.

• Use @min instead of std.math.min
• @truncate only takes one parameter now
• Run zig fmt to autoconvert to the new for loop index syntax (0..)
• Using more specific fmt specifiers to prevent runtime crashes on errors