umans-ai + coding-plan: remove umans-glm-5.1 (no longer served) (#5075)

umans-glm-5.1 has been retired from the umans.ai catalogue. The live
catalog (GET https://api.code.umans.ai/v1/models) no longer lists it, so
drop it from both the pay-per-token provider and the coding plan.
Everything else is unchanged.

providers/umans-ai-coding-plan/models/umans-glm-5.1.toml

@@ -1,20 +0,0 @@
-base_model = "zhipuai/glm-5.1"
-name = "GLM 5.1"
-# Live metadata: levels none/medium, default medium, and `can_disable=true`
-# (accessed 2026-06-25): https://api.code.umans.ai/v1/models/info
-reasoning_options = [{ type = "toggle" }]
-
-[interleaved]
-field = "reasoning_content"
-
-[cost]
-input = 0
-output = 0
-cache_read = 0
-cache_write = 0
-
-[limit]
-context = 204_800
-
-[modalities]
-input = ["text", "image"]

providers/umans-ai/models/umans-glm-5.1.toml

@@ -1,20 +0,0 @@
-base_model = "zhipuai/glm-5.1"
-name = "GLM 5.1"
-# Live metadata: levels none/medium, default medium, and `can_disable=true`
-# (accessed 2026-06-25): https://api.code.umans.ai/v1/models/info
-reasoning_options = [{ type = "toggle" }]
-
-[interleaved]
-field = "reasoning_content"
-
-[cost]
-input = 1.40
-output = 4.40
-cache_read = 0.29
-
-[limit]
-context = 204_800
-output = 131_072
-
-[modalities]
-input = ["text", "image"]