use string constant for events consistently

Mic92 · Mic92 · commit 2156e1fa5a3f · 2025-09-10T15:08:44.000+02:00
diff --git a/buildbot_nix/buildbot_nix/__init__.py b/buildbot_nix/buildbot_nix/__init__.py
@@ -181,7 +181,7 @@ async def produce_event(self, event: str, result: None | int) -> None:
         )
 
     async def run(self) -> int:
-        await self.produce_event("started-nix-eval", None)
+        await self.produce_event(CombinedBuildEvent.STARTED_NIX_EVAL.value, None)
 
         branch_config: BranchConfig = await BranchConfig.extract_during_step(self)
 

Original file line number	Diff line number	Diff line change
`@@ -181,7 +181,7 @@ async def produce_event(self, event: str, result: None \| int) -> None:`
`181`	`181`	`)`
`182`	`182`
`183`	`183`	`async def run(self) -> int:`
`184`		`- await self.produce_event("started-nix-eval", None)`
	`184`	`+ await self.produce_event(CombinedBuildEvent.STARTED_NIX_EVAL.value, None)`
`185`	`185`
`186`	`186`	`branch_config: BranchConfig = await BranchConfig.extract_during_step(self)`
`187`	`187`