Don't add artificial newline to last line if --style=plain

This fixes #1438.

Note however, that using a pager such as less will add a newline itself.
So to actually not print a newline for such files, you need to either
disable paging:

  bat --style=plain --paging=never no-newline-at-end-of-file.txt

or use a "pager" that does not add a newline:

  bat --style=plain --pager=cat no-newline-at-end-of-file.txt

Note that we also update syntax tests file since a bunch of them had
missing newlines on the last lines.

tests/syntax-tests/highlighted/Plaintext/plaintext.txt

@@ -175,4 +175,4 @@
 \u{ad}␊
 \u{ae}␊
 ␊
-Here's·a·line·with·multiple·characters.
+Here's·a·line·with·multiple·characters.␊

tests/syntax-tests/source/ActionScript/test.as

@@ -72,4 +72,4 @@ package TestSyntax {
             var sndChannel:SoundChannel = mySound.play();
         }
     }
-}
+}

tests/syntax-tests/source/Batch/build.bat

@@ -56,4 +56,4 @@ set LDLIBS= ^
     @set "LINK_FILES=%LINK_FILES% %%~f"
 )
 
-lld-link.exe %LINK_FILES% -out:"%OUTPUT%" %LDFLAGS% %LDLIBS%
+lld-link.exe %LINK_FILES% -out:"%OUTPUT%" %LDFLAGS% %LDLIBS%

tests/syntax-tests/source/Clojure/test.clj

@@ -55,4 +55,4 @@
     (println (factorial 5))
     (log)
     (log "Message"))
-  
+  

tests/syntax-tests/source/Dockerfile/Dockerfile

@@ -16,4 +16,4 @@ EXPOSE 80/tcp
 
 VOLUME [/var/lib/mysql/data]
 
-ENTRYPOINT ["/usr/bin/entrypoint.sh"]
+ENTRYPOINT ["/usr/bin/entrypoint.sh"]

tests/syntax-tests/source/Git Attributes/example.gitattributes

@@ -13,4 +13,4 @@
 *.patch    -text
 
 .gitattributes linguist-language=gitattributes
-.gitkeep       export-ignore
+.gitkeep       export-ignore

tests/syntax-tests/source/Git Config/text.gitconfig

@@ -104,4 +104,4 @@
 [user]
 	email = f.nord@example.com
 	name = Frank Nord
-	signingkey = AAAAAAAAAAAAAAAA
+	signingkey = AAAAAAAAAAAAAAAA

tests/syntax-tests/source/Hosts/hosts

@@ -5,4 +5,4 @@
 192.160.0.200        try.sample.test try     #another comment
 216.58.223.238       google.com
 
-::1 localhost.try ip6-localhost
+::1 localhost.try ip6-localhost

tests/syntax-tests/source/Makefile/Makefile

@@ -382,4 +382,4 @@ install: all
 	@ln -sf $(REDIS_SERVER_NAME) $(INSTALL_BIN)/$(REDIS_SENTINEL_NAME)
 
 uninstall:
-	rm -f $(INSTALL_BIN)/{$(REDIS_SERVER_NAME),$(REDIS_BENCHMARK_NAME),$(REDIS_CLI_NAME),$(REDIS_CHECK_RDB_NAME),$(REDIS_CHECK_AOF_NAME),$(REDIS_SENTINEL_NAME)}
+	rm -f $(INSTALL_BIN)/{$(REDIS_SERVER_NAME),$(REDIS_BENCHMARK_NAME),$(REDIS_CLI_NAME),$(REDIS_CHECK_RDB_NAME),$(REDIS_CHECK_AOF_NAME),$(REDIS_SENTINEL_NAME)}

tests/syntax-tests/source/PHP/test.php

@@ -108,4 +108,4 @@ $doe->setName('John Doe');
 
 $ending = 2 > 3 ? "yep" : "nah";
 
-?>
+?>

tests/syntax-tests/source/RequirementsTXT/requirements.txt

@@ -5,4 +5,4 @@ pywheels>=12.4 #a whitespace followed by comments
 Nuitka<0.6.8.4
 wxPython>=1.0, <=2.1
 
-#this is another comment
+#this is another comment

tests/syntax-tests/source/YAML/example.yaml

@@ -31,4 +31,4 @@ emails:
       - bob@example.com
       - bill@example.com
     supervisors:
-      - george@example.com
+      - george@example.com

tests/syntax-tests/source/reStructuredText/reference.rst

@@ -317,4 +317,4 @@ blank lines before and after.)
 ..
 
         So this block is not "lost",
-        despite its indentation.
+        despite its indentation.