texinfo: fix emission of @footnote directives.

Right now, labels are emitted as part of a @footnote directive.
That results in e.g.

Note1: (@footnote{@w{(1)}
Future versions of GCC may zero-extend...
})

which is incorrect and should be rather:

Note1: (@footnote{Future versions of GCC may zero-extend...})

1 files changed, 9 insertions, 3 deletions

diff --git a/sphinx/writers/texinfo.py b/sphinx/writers/texinfo.py
index 6df558323..ebb05d9ab 100644
--- a/sphinx/writers/texinfo.py
+++ b/sphinx/writers/texinfo.py
@@ -761,10 +761,12 @@ class TexinfoTranslator(SphinxTranslator):
     # -- Blocks
 
     def visit_paragraph(self, node: Element) -> None:
-        self.body.append('\n')
+        if not self.in_footnote:
+            self.body.append('\n')
 
     def depart_paragraph(self, node: Element) -> None:
-        self.body.append('\n')
+        if not self.in_footnote:
+            self.body.append('\n')
 
     def visit_block_quote(self, node: Element) -> None:
         self.body.append('\n@quotation\n')
@@ -1223,7 +1225,11 @@ class TexinfoTranslator(SphinxTranslator):
         self.depart_topic(node)
 
     def visit_label(self, node: Element) -> None:
-        self.body.append('@w{(')
+        # label numbering is automatically generated by Texinfo
+        if self.in_footnote:
+            raise nodes.SkipNode
+        else:
+            self.body.append('@w{(')
 
     def depart_label(self, node: Element) -> None:
         self.body.append(')} ')