Panic "missing operation context" when body fails to parse on GetOperationContext with prometheus extension

### What happened?
Panic during extension evaluation while when the body fails to parse.

### What did you expect?
Normal error response

### Minimal graphql.schema and models to reproduce
N/A

### versions
- `go run github.com/99designs/gqlgen version`: v0.17.34
- `go version`: go version go1.20.7 linux/amd64

I get the following panic:
```
missing operation context

goroutine 119 [running]:
runtime/debug.Stack()
/usr/local/go/src/runtime/debug/stack.go:24 +0x65
runtime/debug.PrintStack()
/usr/local/go/src/runtime/debug/stack.go:16 +0x19
github.com/99designs/gqlgen/graphql.DefaultRecover({0x0?, 0x8?}, {0x1097a40?, 0x1414270?})
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/recovery.go:17 +0x71
github.com/99designs/gqlgen/graphql/executor.(*Executor).PresentRecoveredError(0xc000260140, {0x142ef98, 0xc0005fea50}, {0x1097a40?, 0x1414270?})
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/executor/executor.go:156 +0x46
github.com/99designs/gqlgen/graphql/handler.(*Server).ServeHTTP.func1()
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/handler/server.go:104 +0x99
panic({0x1097a40, 0x1414270})
/usr/local/go/src/runtime/panic.go:884 +0x212
github.com/99designs/gqlgen/graphql.GetOperationContext({0x142ef98?, 0xc0005feab0?})
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/context_operation.go:65 +0x71
github.com/99designs/gqlgen-contrib/prometheus.Tracer.InterceptResponse({}, {0x142ef98, 0xc0005feab0}, 0xc0002af128)
/go/pkg/mod/github.com/99designs/gqlgen-contrib@v0.1.1-0.20230605152740-d49a0a0239a7/prometheus/prometheus.go:129 +0x45
github.com/99designs/gqlgen/graphql/executor.processExtensions.func6({0x142ef98, 0xc0005feab0}, 0x12db030)
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/executor/extensions.go:91 +0xb0
github.com/99designs/gqlgen/graphql/executor.processExtensions.func6.1({0x142ef98?, 0xc0005feab0?})
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/executor/extensions.go:92 +0x2b
github.com/ravilushqa/otelgqlgen.Tracer.InterceptResponse({{0x0, 0x0}, {0x1422560, 0xc0000a99c0}, 0x12dbc30, 0x12dbc28}, {0x142ef98, 0xc0005feab0}, 0xc0002af110)
/go/pkg/mod/github.com/ravilushqa/otelgqlgen@v0.13.1/gqlgen.go:63 +0x879
github.com/99designs/gqlgen/graphql/executor.processExtensions.func6({0x142ef98, 0xc0005feab0}, 0x12db030)
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/executor/extensions.go:91 +0xb0
github.com/99designs/gqlgen/graphql/executor.(*Executor).DispatchError(0xc000260140, {0x142ef98, 0xc0005fea50}, {0xc0000125a8, 0x1, 0xc0005fea80?})
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/executor/executor.go:144 +0x11c
github.com/99designs/gqlgen/graphql/handler/transport.POST.Do({0x142eef0?}, {0x7ff796a4ed40?, 0xc000107200}, 0xc000107900, {0x142b830, 0xc000260140})
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/handler/transport/http_post.go:76 +0x6b0
github.com/99designs/gqlgen/graphql/handler.(*Server).ServeHTTP(0xc00007c6c0, {0x7ff796a4ed40, 0xc000107200}, 0xc000107900)
/go/pkg/mod/github.com/99designs/gqlgen@v0.17.36/graphql/handler/server.go:121 +0x212
...
github.com/gin-gonic/gin.(*Context).Next(...)
/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:174
github.com/gin-gonic/gin.(*Engine).handleHTTPRequest(0xc000007860, 0xc000107200)
/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/gin.go:620 +0x671
github.com/gin-gonic/gin.(*Engine).ServeHTTP(0xc000007860, {0x142df00?, 0xc000158fc0}, 0xc000107800)
/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/gin.go:576 +0x1dd
net/http.serverHandler.ServeHTTP({0x1429db0?}, {0x142df00, 0xc000158fc0}, 0xc000107800)
/usr/local/go/src/net/http/server.go:2947 +0x30c
net/http.(*conn).serve(0xc000260f00, {0x142ef98, 0xc0001b3980})
/usr/local/go/src/net/http/server.go:1991 +0x607
created by net/http.(*Server).Serve
/usr/local/go/src/net/http/server.go:3102 +0x4db
```

When the body fails to parse and i use the gqlgen-contrib/prmetheus extension:
```
import gqlprom "github.com/99designs/gqlgen-contrib/prometheus"
graphqlHandler.Use(gqlprom.Tracer{})
```

I see that there is a `WithOperationContext` on line 84
```
resp := exec.DispatchError(graphql.WithOperationContext(ctx, rc), OpErr)
```
but not on line 76, so maybe all error cases are not covered (maybe related to https://github.com/99designs/gqlgen/issues/1067) ?