build: automate version resolution in build.zig

Removes manual git flags from CI and build scripts.
Versioning is now automatically derived from git and build.zig.zon.

With this PR, we follow https://semver.org/
Logic:

1. Read the version from build.zig.zon
2. If it doesn't have a `.pre` field (i.e. dev/alpha/beta) it will use that
3. Otherwise it will get the info from git: hash and number of commits since last `.0` version
4. Then build the version: `0.3.0-dev.1493+0896edc3`

Note that, since the latest stable version is `0.2.6`.
The convention is to use `0.3.0-dev`, as:
- `0.2.6` < `0.3.0.dev` < `0.3.0`

src/crash_handler.zig

@@ -47,7 +47,7 @@ pub noinline fn crash(
                 writer.print("\nreason: {s}\n", .{reason}) catch abort();
                 writer.print("OS: {s}\n", .{@tagName(builtin.os.tag)}) catch abort();
                 writer.print("mode: {s}\n", .{@tagName(builtin.mode)}) catch abort();
-                writer.print("version: {s}\n", .{lp.build_config.git_commit}) catch abort();
+                writer.print("version: {s}\n", .{lp.build_config.version}) catch abort();
                 inline for (@typeInfo(@TypeOf(args)).@"struct".fields) |f| {
                     writer.writeAll(f.name ++ ": ") catch break;
                     @import("log.zig").writeValue(.pretty, @field(args, f.name), writer) catch abort();
@@ -86,7 +86,7 @@ fn report(reason: []const u8, begin_addr: usize, args: anytype) !void {
     var url_buffer: [4096]u8 = undefined;
     const url = blk: {
         var writer: std.Io.Writer = .fixed(&url_buffer);
-        try writer.print("https://crash.lightpanda.io/c?v={s}&r=", .{lp.build_config.git_commit});
+        try writer.print("https://crash.lightpanda.io/c?v={s}&r=", .{lp.build_config.version});
         for (reason) |b| {
             switch (b) {
                 'A'...'Z', 'a'...'z', '0'...'9', '-', '.', '_' => try writer.writeByte(b),

src/main.zig

@@ -59,11 +59,8 @@ fn run(allocator: Allocator, main_arena: Allocator) !void {
             return std.process.cleanExit();
         },
         .version => {
-            if (lp.build_config.git_version) |version| {
-                std.debug.print("{s} ({s})\n", .{ version, lp.build_config.git_commit });
-            } else {
-                std.debug.print("{s}\n", .{lp.build_config.git_commit});
-            }
+            var stdout = std.fs.File.stdout().writer(&.{});
+            try stdout.interface.print("{s}\n", .{lp.build_config.version});
             return std.process.cleanExit();
         },
         else => {},

src/telemetry/lightpanda.zig

@@ -145,7 +145,7 @@ const LightPandaEvent = struct {
         try writer.write(builtin.cpu.arch);
 
         try writer.objectField("version");
-        try writer.write(build_config.git_version orelse build_config.git_commit);
+        try writer.write(build_config.version);
 
         try writer.objectField("event");
         try writer.write(@tagName(std.meta.activeTag(self.event)));