Fix a few edge case bugs with hybrid ssr:false/prerender scenarios (#13021)

Author: brophdawg11

.changeset/nice-wombats-perform.md

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+---
+"react-router": patch
+---
+
+Properly handle revalidations to across a prerender/SPA boundary
+
+- In "hybrid" applications where some routes are pre-rendered and some are served from a SPA fallback, we need to avoid making `.data` requests if the path wasn't pre-rendered because the request will 404
+- We don't know all the pre-rendered paths client-side, however:
+  - All `loader` data in `ssr:false` mode is static because it's generated at build time
+  - A route must use a `clientLoader` to do anything dynamic
+  - Therefore, if a route only has a `loader` and not a `clientLoader`, we disable revalidation by default because there is no new data to retrieve
+  - We short circuit and skip single fetch `.data` request logic if there are no server loaders with `shouldLoad=true` in our single fetch `dataStrategy`
+  - This ensures that the route doesn't cause a `.data` request that would 404 after a submission

.changeset/nice-wombats-perform2.md

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+---
+"react-router": patch
+---
+
+Error at build time in `ssr:false` + `prerender` apps for the edge case scenario of:
+
+- A parent route has only a `loader` (does not have a `clientLoader`)
+- The parent route is pre-rendered
+- The parent route has children routes which are not prerendered
+- This means that when the child paths are loaded via the SPA fallback, the parent won't have any `loaderData` because there is no server on which to run the `loader`
+- This can be resolved by either adding a parent `clientLoader` or pre-rendering the child paths
+- If you add a `clientLoader`, calling the `serverLoader()` on non-prerendered paths will throw a 404