Revert "fixup! Tor Browser localization migration scripts."

This reverts commit 57b8a1d5.

tools/torbrowser/l10n/migrations/bug-42211-new-identity.py

-import fluent.syntax.ast as FTL
-from fluent.migrate.helpers import TERM_REFERENCE, transforms_from
-from fluent.migrate.transforms import REPLACE
-
-
-def migrate(ctx):
-    legacy_path = "newIdentity.properties"
-
-    ctx.add_transforms(
-        "base-browser.ftl",
-        "base-browser.ftl",
-        transforms_from(
-            """
-menu-new-identity =
-    .label = { COPY(path, "new_identity") }
-    .accesskey = { COPY(path, "new_identity_menu_accesskey") }
-appmenuitem-new-identity =
-    .label = { COPY(path, "new_identity_sentence_case") }
-toolbar-new-identity =
-    .label = { COPY(path, "new_identity_sentence_case") }
-    .tooltiptext = { toolbar-new-identity.label }
-
-new-identity-dialog-title = { COPY(path, "new_identity_prompt_title") }
-new-identity-dialog-never-ask-checkbox =
-    .label = { COPY(path, "new_identity_ask_again") }
-
-new-identity-blocked-home-ignore-button = { COPY(path, "new_identity_home_load_button") }
-""",
-            path=legacy_path,
-        )
-        + [
-            # Replace "%S" with "{ -brand-short-name }" in confirm button.
-            FTL.Message(
-                id=FTL.Identifier("new-identity-dialog-confirm"),
-                value=None,
-                attributes=[
-                    FTL.Attribute(
-                        id=FTL.Identifier("label"),
-                        value=REPLACE(
-                            legacy_path,
-                            "new_identity_restart",
-                            {"%1$S": TERM_REFERENCE("brand-short-name")},
-                        ),
-                    ),
-                ],
-            ),
-        ],
-    )