fix(lsp): revert buf_versions deprecation/replacement (#29217)

* Revert "fix(lsp): account for changedtick version gap on modified reset (#29170)"

This reverts commit 2e6d295f79.

* Revert "refactor(lsp): replace util.buf_versions with changedtick (#28943)"

This reverts commit 5c33815448.

test/functional/plugin/lsp/semantic_tokens_spec.lua

@@ -111,7 +111,6 @@ describe('semantic token highlighting', function()
     end)
 
     it('buffer is highlighted when attached', function()
-      insert(text)
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
@@ -119,6 +118,8 @@ describe('semantic token highlighting', function()
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
+
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -140,7 +141,6 @@ describe('semantic token highlighting', function()
     end)
 
     it('use LspTokenUpdate and highlight_token', function()
-      insert(text)
       exec_lua([[
         vim.api.nvim_create_autocmd("LspTokenUpdate", {
           callback = function(args)
@@ -157,6 +157,8 @@ describe('semantic token highlighting', function()
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
+
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -178,17 +180,14 @@ describe('semantic token highlighting', function()
     end)
 
     it('buffer is unhighlighted when client is detached', function()
-      insert(text)
-
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
-        vim.wait(1000, function()
-          return #server.messages > 1
-        end)
       ]])
 
+      insert(text)
+
       exec_lua([[
         vim.notify = function() end
         vim.lsp.buf_detach_client(bufnr, client_id)
@@ -332,13 +331,14 @@ describe('semantic token highlighting', function()
     end)
 
     it('buffer is re-highlighted when force refreshed', function()
-      insert(text)
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
+
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -412,14 +412,13 @@ describe('semantic token highlighting', function()
     end)
 
     it('updates highlights with delta request on buffer change', function()
-      insert(text)
-
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -598,7 +597,6 @@ describe('semantic token highlighting', function()
     end)
 
     it('does not send delta requests if not supported by server', function()
-      insert(text)
       exec_lua(
         [[
         local legend, response, edit_response = ...
@@ -627,6 +625,7 @@ describe('semantic token highlighting', function()
         edit_response
       )
 
+      insert(text)
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -1450,7 +1449,6 @@ int main()
       },
     }) do
       it(test.it, function()
-        insert(test.text1)
         exec_lua(create_server_definition)
         exec_lua(
           [[
@@ -1487,6 +1485,8 @@ int main()
           test.response2
         )
 
+        insert(test.text1)
+
         test.expected_screen1()
 
         local highlights = exec_lua([[