Revert "lsp-csharp: add a test to check if dotnet tool csharp-ls is actually installed" (#4368)

* treewide: replace `looking-at` with `looking-at-p` if match data unused

`looking-at-p` does not change match data and so should be a bit faster.

* Revert "lsp-csharp: add a test to check if dotnet tool csharp-ls is actually installed"

This reverts commit 9b3a921.

This commit broke detection of `csharp-ls`. I am not sure what was the
purpose of the change. The function it adds says it checks whether
`csharp-ls` is present in the system, however the function
`lsp-csharp--cls-make-launch-cmd` always did the same and better. So
why have this additional check is not at all clear.

The function was assuming that a `dotnet tool list -g` should return
if `csharp-ls` is installed, however for me its output is just empty:

    λ dotnet tool list -g
    Package Id      Version      Commands
    -------------------------------------

Let's revert this commit.

Fixes: #4365

Author: Hi-Angel

clients/lsp-csharp.el

@@ -442,11 +442,6 @@ filename is returned so lsp-mode can display this file."
             (list csharp-ls-exec)
             solution-file-params)))
 
-(defun lsp-csharp--cls-test-csharp-ls-present ()
-  "Return non-nil if dotnet tool csharp-ls is installed globally."
-  (string-match-p "csharp-ls"
-                  (shell-command-to-string "dotnet tool list -g")))
-
 (defun lsp-csharp--cls-download-server (_client callback error-callback update?)
   "Install/update csharp-ls language server using `dotnet tool'.
 
@@ -458,8 +453,7 @@ Will update if UPDATE? is t"
    "dotnet" "tool" (if update? "update" "install") "-g" "csharp-ls"))
 
 (lsp-register-client
- (make-lsp-client :new-connection (lsp-stdio-connection #'lsp-csharp--cls-make-launch-cmd
-                                                        #'lsp-csharp--cls-test-csharp-ls-present)
+ (make-lsp-client :new-connection (lsp-stdio-connection #'lsp-csharp--cls-make-launch-cmd)
                   :priority -2
                   :server-id 'csharp-ls
                   :activation-fn (lsp-activate-on "csharp")

clients/lsp-javascript.el

@@ -888,13 +888,13 @@ with the file contents."
         (unless (re-search-forward "[^\n[:space:]]" nil t)
           (setq stop t))
         (if (= (point) (point-min)) (setq stop t) (backward-char))
-        (cond ((or (looking-at "//+[ ]*@flow")
-                   (looking-at "/\\**[ ]*@flow")
-                   (looking-at "[ ]*\\*[ ]*@flow"))
+        (cond ((or (looking-at-p "//+[ ]*@flow")
+                   (looking-at-p "/\\**[ ]*@flow")
+                   (looking-at-p "[ ]*\\*[ ]*@flow"))
                (setq found t) (setq stop t))
-              ((or (looking-at "//") (looking-at "*"))
+              ((or (looking-at-p "//") (looking-at-p "*"))
                (forward-line))
-              ((looking-at "/\\*")
+              ((looking-at-p "/\\*")
                (save-excursion
                  (unless (re-search-forward "*/" nil t) (setq stop t)))
                (forward-line))

lsp-mode.el

@@ -5230,7 +5230,7 @@ If EXCLUDE-DECLARATION is non-nil, request the server to include declarations."
       lsp--eldoc-saved-message
     (setq lsp--hover-saved-bounds nil
           lsp--eldoc-saved-message nil)
-    (if (looking-at "[[:space:]\n]")
+    (if (looking-at-p "[[:space:]\n]")
         (setq lsp--eldoc-saved-message nil) ; And returns nil.
       (when (and lsp-eldoc-enable-hover (lsp--capability :hoverProvider))
         (lsp-request-async
@@ -5268,7 +5268,7 @@ If EXCLUDE-DECLARATION is non-nil, request the server to include declarations."
 (defun lsp--document-highlight ()
   (when (lsp-feature? "textDocument/documentHighlight")
     (let ((curr-sym-bounds (bounds-of-thing-at-point 'symbol)))
-      (unless (or (looking-at "[[:space:]\n]")
+      (unless (or (looking-at-p "[[:space:]\n]")
                   (not lsp-enable-symbol-highlighting)
                   (and lsp--have-document-highlights
                        curr-sym-bounds