Fix feature flags for solari and meshlets examples (#21474)

# Objective

The `solari` example does not compile when run with the
required-features following #20215.

## Solution

Require the new free_cam feature.

## Testing

`cargo build --example solari --features="bevy_solari https free_cam"`

Author: alice-i-cecile

Cargo.toml

@@ -1313,7 +1313,7 @@ wasm = true
 name = "solari"
 path = "examples/3d/solari.rs"
 doc-scrape-examples = true
-required-features = ["bevy_solari", "https"]
+required-features = ["bevy_solari", "https", "free_cam"]
 
 [package.metadata.example.solari]
 name = "Solari"
@@ -1427,7 +1427,7 @@ wasm = false
 name = "meshlet"
 path = "examples/3d/meshlet.rs"
 doc-scrape-examples = true
-required-features = ["meshlet", "https"]
+required-features = ["meshlet", "https", "free_cam"]
 
 [package.metadata.example.meshlet]
 name = "Meshlet"