Put python object definition and assignment on same line (#3057)

Where there was an object initialization immediately followed by
assignment I condensed it to one line, which seems to be the convention
looking at other files. I also deleted the repetition of 'of' in some
c++ comments because it was grammatically incorrect.

---------

Co-authored-by: Clayton Gearhart <claytongearhart240@gmail.com>

github_tools/pr_comments.py

@@ -239,15 +239,14 @@ class _Thread:
 
     def format(self, long: bool) -> str:
         """Formats the review thread with comments."""
-        lines = []
-        lines.append(
+        lines = [
             "%s\n  - line %d; %s"
             % (
                 self.url,
                 self.line,
                 ("resolved" if self.is_resolved else "unresolved"),
             )
-        )
+        ]
         if self.diff_url:
             lines.append("  - diff: %s" % self.diff_url)
         for comment in self.comments:

migrate_cpp/rewriter.h

@@ -174,7 +174,7 @@ class RewriteBuilder : public clang::RecursiveASTVisitor<RewriteBuilder> {
 };
 
 // An `ASTConsumer` which, when executed, populates a `std::string` with the
-// text of a Carbon source file which is a best approximation of of the
+// text of a Carbon source file which is a best approximation of the
 // semantics of the corresponding C++ translation unit defined by the consumed
 // AST.
 class MigrationConsumer : public clang::ASTConsumer {
@@ -193,7 +193,7 @@ class MigrationConsumer : public clang::ASTConsumer {
 
 // An `ASTFrontendAction` which constructs a `MigrationConsumer` and invokes it
 // on an AST, populating a `std::string` with the text of a Carbon source file
-// which is a best approximation of of the semantics of the corresponding C++
+// which is a best approximation of the semantics of the corresponding C++
 // translation unit defined by the consumed AST.
 class MigrationAction : public clang::ASTFrontendAction {
  public:

scripts/fix_cc_deps.py

@@ -251,9 +251,10 @@ def main() -> None:
     external_rules = get_rules(bazel, external_repo_query, True)
 
     print("Building header map...")
-    header_to_rule_map: Dict[str, Set[str]] = {}
-    header_to_rule_map["gmock/gmock.h"] = {"@com_google_googletest//:gtest"}
-    header_to_rule_map["gtest/gtest.h"] = {"@com_google_googletest//:gtest"}
+    header_to_rule_map: Dict[str, Set[str]] = {
+        "gmock/gmock.h": {"@com_google_googletest//:gtest"},
+        "gtest/gtest.h": {"@com_google_googletest//:gtest"},
+    }
     map_headers(header_to_rule_map, carbon_rules)
     map_headers(header_to_rule_map, external_rules)