Merge bitcoin/bitcoin#26707: clang-tidy: Fix performance-*move* warnings in headers

1308b83 clang-tidy: Fix `performance-no-automatic-move` in headers (Hennadii Stepanov)
0a5dc03 clang-tidy: Fix `performance-move-const-arg` in headers (Hennadii Stepanov)

Pull request description:

  Split from bitcoin/bitcoin#26705 as was requested in bitcoin/bitcoin#26705 (comment).

  To test this PR, consider applying a diff as follows:
  ```diff
  --- a/src/.clang-tidy
  +++ b/src/.clang-tidy
  @@ -1,16 +1,7 @@
   Checks: '
   -*,
  -bugprone-argument-comment,
  -bugprone-use-after-move,
  -misc-unused-using-decls,
  -modernize-use-default-member-init,
  -modernize-use-nullptr,
  -performance-for-range-copy,
   performance-move-const-arg,
   performance-no-automatic-move,
  -performance-unnecessary-copy-initialization,
  -readability-redundant-declaration,
  -readability-redundant-string-init,
   '
   WarningsAsErrors: '
   bugprone-argument-comment,
  @@ -28,4 +19,4 @@ readability-redundant-string-init,
   CheckOptions:
    - key: performance-move-const-arg.CheckTriviallyCopyableMove
      value: false
  -HeaderFilterRegex: './qt'
  +HeaderFilterRegex: '.'
  ```

ACKs for top commit:
  fanquake:
    ACK 1308b83

Tree-SHA512: b7ef9a3e789846130ab4c3fd6fbe8d887bdbcd438e4cbc78e2b1ac01f819ae13d7f69c2a25f480bd36e3e7f58886a7d5a8609a3c3275c315e0697cd4010474bd

Author: MarcoFalke

src/fs.h

@@ -35,7 +35,7 @@ class path : public std::filesystem::path
     // Allow path objects arguments for compatibility.
     path(std::filesystem::path path) : std::filesystem::path::path(std::move(path)) {}
     path& operator=(std::filesystem::path path) { std::filesystem::path::operator=(std::move(path)); return *this; }
-    path& operator/=(std::filesystem::path path) { std::filesystem::path::operator/=(std::move(path)); return *this; }
+    path& operator/=(std::filesystem::path path) { std::filesystem::path::operator/=(path); return *this; }
 
     // Allow literal string arguments, which are safe as long as the literals are ASCII.
     path(const char* c) : std::filesystem::path(c) {}

src/script/miniscript.h

@@ -1378,7 +1378,7 @@ inline NodeRef<Key> Parse(Span<const char> in, const Ctx& ctx)
     assert(constructed.size() == 1);
     assert(constructed[0]->ScriptSize() == script_size);
     if (in.size() > 0) return {};
-    const NodeRef<Key> tl_node = std::move(constructed.front());
+    NodeRef<Key> tl_node = std::move(constructed.front());
     tl_node->DuplicateKeyCheck(ctx);
     return tl_node;
 }
@@ -1813,7 +1813,7 @@ inline NodeRef<Key> DecodeScript(I& in, I last, const Ctx& ctx)
         }
     }
     if (constructed.size() != 1) return {};
-    const NodeRef<Key> tl_node = std::move(constructed.front());
+    NodeRef<Key> tl_node = std::move(constructed.front());
     tl_node->DuplicateKeyCheck(ctx);
     // Note that due to how ComputeType works (only assign the type to the node if the
     // subs' types are valid) this would fail if any node of tree is badly typed.