gh-75371: reformat Makefile.pre.in to accommodate for empty FRAMEWORKALTINSTALLLAST (#107035)

in the case of an empty FRAMEWORKALTINSTALLLAST, this patch prevents leaving
an astray linebreak and two tabs in the resulting Makefile.

Before change:
```
.PHONY: commoninstall
commoninstall:  check-clean-src  \
		altbininstall libinstall inclinstall libainstall \
		sharedinstall altmaninstall \

```

After change (with empty FRAMEWORKALTINSTALLLAST):
```
.PHONY: commoninstall
commoninstall:  check-clean-src  \
		altbininstall libinstall inclinstall libainstall \
		sharedinstall altmaninstall
```

Author: zormit

Makefile.pre.in

@@ -1940,8 +1940,7 @@ altinstall: commoninstall
 .PHONY: commoninstall
 commoninstall:  check-clean-src @FRAMEWORKALTINSTALLFIRST@ \
 		altbininstall libinstall inclinstall libainstall \
-		sharedinstall altmaninstall \
-		@FRAMEWORKALTINSTALLLAST@
+		sharedinstall altmaninstall @FRAMEWORKALTINSTALLLAST@
 
 # Install shared libraries enabled by Setup
 DESTDIRS=	$(exec_prefix) $(LIBDIR) $(BINLIBDEST) $(DESTSHARED)