I’m not sure what you want to disable exactly but you should look at eglot-ignored-server-capabilities:

For example to disable inlay hints: (setq eglot-ignored-server-capabilities '(:inlayHintProvider)).

Here is the complete list of server capabilities:

          (const :tag "Documentation on hover" :hoverProvider)
          (const :tag "Code completion" :completionProvider)
          (const :tag "Function signature help" :signatureHelpProvider)
          (const :tag "Go to definition" :definitionProvider)
          (const :tag "Go to type definition" :typeDefinitionProvider)
          (const :tag "Go to implementation" :implementationProvider)
          (const :tag "Go to declaration" :declarationProvider)
          (const :tag "Find references" :referencesProvider)
          (const :tag "Highlight symbols automatically" :documentHighlightProvider)
          (const :tag "List symbols in buffer" :documentSymbolProvider)
          (const :tag "List symbols in workspace" :workspaceSymbolProvider)
          (const :tag "Execute code actions" :codeActionProvider)
          (const :tag "Code lens" :codeLensProvider)
          (const :tag "Format buffer" :documentFormattingProvider)
          (const :tag "Format portion of buffer" :documentRangeFormattingProvider)
          (const :tag "On-type formatting" :documentOnTypeFormattingProvider)
          (const :tag "Rename symbol" :renameProvider)
          (const :tag "Highlight links in document" :documentLinkProvider)
          (const :tag "Decorate color references" :colorProvider)
          (const :tag "Fold regions of buffer" :foldingRangeProvider)
          (const :tag "Execute custom commands" :executeCommandProvider)
          (const :tag "Inlay hints" :inlayHintProvider)