Pipeline schedules with inputs are broken in v18.10
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## Bug Report
Pipeline schedules with inputs configured breaks the provider in version v18.10 as inputs are [presumed ](https://gitlab.com/gitlab-org/terraform-provider-gitlab/-/blob/main/internal/provider/resource_gitlab_pipeline_schedule.go?ref_type=heads#L197) to always be `string` which is not the case.
```golang
Stack trace from the terraform-provider-gitlab_v18.10.0 plugin:
panic: interface conversion: interface {} is bool, not string
goroutine 7968 [running]:
gitlab.com/gitlab-org/terraform-provider-gitlab/internal/provider.(*gitlabPipelineScheduleResource).pipelineScheduleToStateModel(0x1a08aa6?, {0x1b15608, 0x27bd054e35c0}, {0x27bd04248f10?, 0x2?}, 0x27bd05c7abb0, 0x27bd0653f1d0)
gitlab.com/gitlab-org/terraform-provider-gitlab/internal/provider/resource_gitlab_pipeline_schedule.go:197 +0xae9
gitlab.com/gitlab-org/terraform-provider-gitlab/internal/provider.(*gitlabPipelineScheduleResource).Read(0x27bd06280210, {0x1b15608, 0x27bd054e35c0}, {{{{0x1b25d60, 0x27bd057f9e30}, {0x17a07a0, 0x27bd057f9b30}}, {0x1b396f8, 0x27bd046073b0}}, 0x0, ...}, ...)
gitlab.com/gitlab-org/terraform-provider-gitlab/internal/provider/resource_gitlab_pipeline_schedule.go:369 +0x728
github.com/hashicorp/terraform-plugin-framework/internal/fwserver.(*Server).ReadResource(0x27bd03791888, {0x1b15608, 0x27bd054e35c0}, 0x27bd04c7f4a0, 0x27bd03e2f568)
github.com/hashicorp/terraform-plugin-framework@v1.19.0/internal/fwserver/server_readresource.go:156 +0xbdc
github.com/hashicorp/terraform-plugin-framework/internal/proto6server.(*Server).ReadResource(0x27bd03791888, {0x1b15608?, 0x27bd054e3380?}, 0x27bd04c7f400)
github.com/hashicorp/terraform-plugin-framework@v1.19.0/internal/proto6server/server_readresource.go:71 +0x585
github.com/hashicorp/terraform-plugin-mux/tf6muxserver.(*muxServer).ReadResource(0x27bd036c2990, {0x1b15608?, 0x27bd054e30b0?}, 0x27bd04c7f400)
github.com/hashicorp/terraform-plugin-mux@v0.23.0/tf6muxserver/mux_server_ReadResource.go:35 +0x190
github.com/hashicorp/terraform-plugin-go/tfprotov6/tf6server.(*server).ReadResource(0x27bd036fa5a0, {0x1b15608?, 0x27bd05941320?}, 0x27bd04df7810)
github.com/hashicorp/terraform-plugin-go@v0.31.0/tfprotov6/tf6server/server.go:864 +0x2f3
github.com/hashicorp/terraform-plugin-go/tfprotov6/internal/tfplugin6._Provider_ReadResource_Handler({0x19cf1e0, 0x27bd036fa5a0}, {0x1b15608, 0x27bd05941320}, 0x27bd04f39a00, 0x0)
github.com/hashicorp/terraform-plugin-go@v0.31.0/tfprotov6/internal/tfplugin6/tfplugin6_grpc.pb.go:925 +0x1a9
google.golang.org/grpc.(*Server).processUnaryRPC(0x27bd036be908, {0x1b15608, 0x27bd05941290}, 0x27bd03fd1380, 0x27bd03405da0, 0x29ed258, 0x0)
google.golang.org/grpc@v1.79.2/server.go:1426 +0x11d2
google.golang.org/grpc.(*Server).handleStream(0x27bd036be908, {0x1b163f8, 0x27bd0350c000}, 0x27bd03fd1380)
google.golang.org/grpc@v1.79.2/server.go:1830 +0xdc6
google.golang.org/grpc.(*Server).serveStreams.func2.1()
google.golang.org/grpc@v1.79.2/server.go:1061 +0x7f
created by google.golang.org/grpc.(*Server).serveStreams.func2 in goroutine 29
google.golang.org/grpc@v1.79.2/server.go:1072 +0x11d
Error: The terraform-provider-gitlab_v18.10.0 plugin crashed!
```
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## Relevant Terraform Configuration
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## Relevant Terraform Command
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terraform ...
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## Relevant Log Output
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<summary>These are the debug logs of the `terraform` command output:</summary>
```plaintext
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## Additional Details
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- GitLab Terraform Provider Version: ``
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- License Tier: `Free|Premium|Ultimate`
issue