relax the go directive to 1.25.0

go 1.26.5 forced every go install user onto the newest toolchain
patch: the go command auto-switches or refuses when the local
toolchain is older than the directive. Nothing in the module needs
1.26 -- the newest constructs are WaitGroup.Go (1.25), SplitSeq and
T.Context (1.24) -- and the strictest dependency, the MCP go-sdk,
declares 1.25.0, which is also why tidy pins the three-part form
rather than a bare 1.25.

Verify: go build, go vet (stdversion), go test -race, and lint against
a 1.25 language version; CI resolves the toolchain from go.mod and
revalidates on an actual 1.25.x.

Author: xobotyi

go.mod

@@ -1,6 +1,6 @@
 module dev.gaijin.team/go/go-gerrit-mcp
 
-go 1.26.5
+go 1.25.0
 
 require (
 	dev.gaijin.team/go/golib v0.8.1